


But Somebody Came

by Bookwormgal



Category: Undertale (Video Game)
Genre: Attempted Undertale Genocide Run, Chara Possessing Frisk, Chara Versus Frisk, F/F, Families of Choice, Fight Scenes, Friendship, Gen, Genocide Versus Pacifist Showdown, Good W. D. Gaster, Goopy W. D. Gaster, Guilt, Implied Suicide to Reset Timeline, Magic, Magic-User Frisk, Memories, Multiple Timelines, Near Death Experiences, Nightmares, Nonbinary Chara and Frisk, POV Third Person Limited, Parent W. D. Gaster, Parent-Child Relationship, Post-Undertale Pacifist Route - "I want to stay with you.", Sans Doesn't Remember Resets, Souls, Spoilers - Undertale Genocide Route, Spoilers - Undertale Pacifist Route, Stable Time Loop, Time Shenanigans, Undertale Reset Issues, Undertale Saves and Resets
Language: English
Status: Completed
Published: 2016-11-19
Updated: 2016-12-24
Packaged: 2018-08-31 20:07:13
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence
Chapters: 6
Words: 30,730
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8591773
Author URL: https://archiveofourown.org/users/Bookwormgal/pseuds/Bookwormgal
Summary: Sans is facing the Human in the corridor, trying to stop them before it is too late. Everyone else he knows is dead. His only hope is to force them to Reset. It was the only way to undo this utter genocide of the monsters.Frisk is living on the surface with his friends and family. The monsters were alive and free after so long and so many mistakes. Then something happens to the broken machine, leaving a strange monster behind while another vanishes. Their friend is in danger in a timeline that no longer happened, so Frisk faces a demon of the past to save him: Chara.





	1. Chapter 1

**Author's Note:**

> Well, I know I shouldn't be writing yet another story while in the midst of juggling so many. But this one should be shorter than most of my works. And the idea wouldn't leave me alone. The characters, the rather colorful world, and interesting concepts of the game all combined into something that was too inspirational to ignore.
> 
> And yes, I wanted to see how a showdown between Pacifist Route Frisk and Genocide Route Frisk/Chara would turn out. The idea filled me with determination.
> 
> Quick note for my usual readers. I actually end up using stronger language in this story than I normally use. But that's because I'm quoting Sans near the end of the Genocide Route during his speech. And even then, it isn't really that bad. It would barely qualify for PG-13 by even the strictest rating system. But since I never use any strong language in my writing due to personal preference and my normal readers are probably used to that fact by now, I figured I'd mention it.
> 
> Oh, and spoilers. Spoilers for any and all routes.

Silence. Deafening and smothering silence wrapped around him. The stupid prophecy was coming true in the most horrifying manner possible. The Underground was growing empty. The Human left behind a trail of dust and silence wherever they went. Even with the knowledge that some force, an anomaly, kept twisting and rearranging the timeline so that no event was necessarily set in stone, he couldn't ignore the countless deaths anymore.

No, not countless. He'd counted them. He stood by and counted every single life lost. Neighbors… Friends… Family…

Sorrow and despair filled his Soul as he fought back the tears flooding his eyes sockets. It hurt. His brother still believed and hoped the Human could be saved right until the end. And the child, already barely recognizable as human even then, killed him without a word. Papyrus dissolved into dust and Sans just let it happen. And something inside him just broke.

It didn't matter. Sans tried to tell himself that a hundred times, trying to embrace the exhausting apathy that he was drowning in before. The anomaly would Reset everything. He couldn't remember the other timelines, but he was smart and he could detect the alterations with the partially-broken machine hidden at home. Sans knew the Human didn't cause _all_ the changes since those started before their arrival, but Sans also knew they had the power to Save. And if they could Save, then they could Reset. All those deaths wouldn't matter because they would Reset and no one would remember. Nothing but a few nightmares would carry over. Sans told himself that as more monster were lost. It would all be undone soon enough.

But something told him that things were approaching the point of no return. If the Human didn't Reset soon, there would be no going back. If the Human didn't stop, all those deaths would remain permanent. Papyrus would be gone forever…

He tucked his hand into his coat pocket and rubbed the scrap of red scarf between his fingers. Sans pushed down all his fear, despair, and hopelessness at the situation. It was so much easier when he felt too tired and numb for events to affect him like this. He couldn't win a fight against the Human. They could reload their Save and try as many times as necessary. He literally couldn't beat them. The best he could do was throw as much power as he could and hope it would frustrate them into giving up. Otherwise… he'd die too. He'd die and they would reach that point of no return.

This was the only chance left. He couldn't stand idly by this time. Everything could be reversed and rendered meaningless, but that's what Sans _wanted_. He wanted a better timeline.

The Human was in New Home now, probably searching for any monsters left to slaughter. There was time before they reached the corridor before the throne room. He would face the Human there, giving them all the chances possible to Reset first. He knew a shortcut there. He just needed to wait.

He hated this. He hated everything about this. He hated the promise he made that stayed his hand for so long. He hated that the Human refused to take the second chance Papyrus offered, throwing that Mercy aside to kill him. He hated how he could only bring himself to care when things had gone too far.

Sans closed his eyes. This wasn't how it was supposed to be. Something deep in his Soul, not quite a feeling and not quite a memory, told him this was wrong. This wasn't how it was supposed to go for all of them.

* * *

Life on the surface with all the freed monsters was never boring. Case in point, magic.

Humanity knew they once used magic and kept trying various methods to reawakening that power. They couldn't remember how to use their magic. People had been trying for centuries. The closest they could manage was sometimes items in certain people's possession would pick up power and traits, but that mostly happened to children for some reason. And even when people gathered the children suspected to have the greatest potential for magic and tried everything they could possibly imagine to get a positive result, none of them succeeded.

Though maybe the greatest minds on the surface should have reconsidered keeping the children "donated" or "discovered" for their studies within sight of a cursed mountain that no one dared to approach. Escaping children with no other options or plans might see the appeal of disappearing or at least going somewhere no one would follow.

Frisk didn't encounter magic, _real_ magic, until they fell down the opening of Mt. Ebott. Monsters were mostly made of magic, so they would never forget or lose the ability to use it. Humanity was mostly matter with their small amount of magic stored in their Soul. But since humans didn't need magic to maintain their body, that small amount of magic made their Souls particularly strong. Especially with some Determination.

But the world was changing as humanity and monsters exchanged information again. Humans were learning about magic again, even if most still didn't know how to access it themselves yet.

Frisk had a bit of a head start when it came to being exposed to magic. Their Soul was yanked around and attacked dozens of times during their journey through the Underground. Magic of every color wrapped around their Soul, shifting the attributes so fights became more difficult. But the closest thing to using magic they achieved on that journey was Saves and Resets. And they still didn't know for certain if that power actually counted as magic or something else. They just knew Determination made it possible.

Even after all this time, Frisk didn't know everything about the power. They didn't know why it only started when they fell into the Underground or if the other children who fell could do the same. The late night talks with Sans, the only person who knew about the multiple timelines and wasn't a talking flower, couldn't answer all their questions. Neither of them had all the answers. They knew that it took a lot of Determination to achieve, they could do it even in death, they could remember all the Saves of a timeline, and that the memories of Resets took longer to return and were imperfect. Memories of Resets came back slowly and were usually blurry or fragmented. If it was a form of magic, it was unlike anything else they'd seen.

But they were starting to learn magic since returning to surface; magic that was definitely magic. Toriel seemed eager to teach her new child and Frisk was determined to learn. They'd tried to learn the magic fire spells that Toriel used or even the simplest magic bullet patterns that the monsters could create, though Frisk certainly didn't intend to use them to hurt anyone. Toriel even tried teaching them healing magic, thinking perhaps that the more difficult form of magic would come more naturally with their temperament. But no matter what the child tried, they couldn't use the magic on others or the world. None of the techniques the monsters used worked for Frisk, so they tried something different. Rather than using magic on others, the child focused on using it on their own Soul.

Lying lazily on their bed, Frisk summoned their Soul. They ignored the uncomfortable tug as the red shape floated out. In the Underground, someone else always drew the Soul out at the start of an encounter. Now Frisk could do it on their own. They moved it back and forth a little, feeling their body pulled along by the connection. This part didn't require any practice; they knew how to maneuver their Soul after countless fights. The next part still needed work.

Taking a deep breath, they focused on the sensation of their Soul. _Blue_. They concentrated on the memory of facing Papyrus in the fog. He turned their Soul blue, the first magic to transform it like that. They focused on the memory of the surprising weight and how it pulled their Soul down. Frisk tried to recreate that feeling now. _Blue_. They knew how blue magic felt as it coated their Soul.

What did blue magic mean to them? It was gravity and control. It was loud laughter, optimism, remaining true to their beliefs, friendliness, and the smell of bones.

…It was stained glass windows, heart-broken rage, hidden strength, unexpected tricks, and the smell of ketchup and the grease from Grillby's.

Frisk closed their eyes briefly. It took time to remember the other timelines after a Reset and it was mostly fragments compared to the current one, but they remembered enough. Especially in nightmares. Frisk knew what Sans could do, both with blue magic and his other techniques. He could make their Soul decide gravity went in almost any direction rather than just down. But when Sans used his full power to attack the child, Frisk knew they deserved it. He never reached that point in this timeline and Frisk hoped he never would need to.

Finally deciding to take a break, Frisk let their Soul slip back where it belonged and sat up. They weren't sure why blue magic was so difficult. They figured out the magic to turn their Soul green, purple, and yellow. Blue shouldn't be so difficult. And yet it was.

If someone ever needed proof that Papyrus was smarter, stronger, and more skilled than what some people assumed when they met the excitable skeleton, the fact he made the dark blue shade of magic seem so easy would certainly do the trick. Of course Frisk knew Papyrus was actually amazing with magic and had better control than any other monster, able to stop his attack instantly if necessary. Growing up with Sans, with almost no defense and barely any health to protect him, learning perfect control over his magic was a requirement. Accidents could have been fatal otherwise.

Frisk ran their hands over the warm comforter beneath them, letting their thoughts drift. Their room wasn't exactly the biggest or the most impressive. In fact, it was a little smaller than the others in the house since the door opened on the short hallway that held the stairs. But they still loved it because it was _their_ room. It didn't hold the same tragic memories of the bedroom in the cozy house in the Ruins or in the empty tomb-like version in New Home. And it held no connections to the locations of their nightmares of other timelines. This was where Frisk belonged.

So far the town didn't have a lot of buildings. Even with magic, it took time to build. One of the tricks they used to speed up relocation to the surface was to build a few larger structures for monsters to live in together and focus on individual homes later. Frisk rather liked this idea since they ended up with all their best friends and family under the same roof. The main floor was the common area shared by everyone: the kitchen (fireproofed by Alphys), the dining room (chairs of various heights included), a living room with a huge television and three large couches, a library (with the correct spelling on the door), a gym that Undyne used quite often, and an attached garage with space for multiple cars, garden tools, and anything else someone might want to drag in. The second floor held the bedrooms for Frisk, Toriel, Asgore, Sans, Papyrus, Undyne, and Alphys, a balcony that overlooked the living room, and the sole bathroom in the entire building.

Negotiating who got which bedroom was almost as tricky as informing humanity of their new neighbors building a town on Mt. Ebott. Frisk picked the center room, closest to the branched off hallway to the stairs and sandwiched between Sans and Alphys. Sans and Papyrus' rooms were next to each other and so were Alphys and Undyne's rooms. Frisk also knew that Alphys mostly used her room to store her belongs and spent more nights in Undyne's room than her own. And to prevent additional conflict as the pair tried to gradually move forward, Toriel and Asgore stayed at opposite ends of the house from each other. In the end, they managed to find a combination that worked for everyone. Frisk even occasionally wondered if they could continue living together even after they finished building the school, the new Grillby's, a power relay station to channel energy from the Core, and a few other buildings and necessities. It was nice having so many people around who cared about them.

But even in such a full house, their room was relatively empty still. There was a lamp in the corner, a wardrobe for their clothes, and a bed against the wall. Other than their clothes and a few items they collected from the Underground, there was only one other feature in the room. A mirror hung on the wall beyond the foot of their bed. They'd insisted on it.

Their reflection showed an eight year old child with a calm expression. They still wore their blue-and-pink striped shirt, any tears from their journey long since repaired. Their brown hair was at just the perfect length: not so short that they couldn't tie it, but not so long that it was in the way the days they left it down. They still looked exactly like they did when they first fell into the Underground.

Frisk liked the reassurance. They liked knowing that even with everything that happened, they made it through as themselves in the end rather than letting the experiences change them. That thought always filled them with Determination.

Despite everything, it's still you.

A sound simultaneously like the tearing of cloth, the shattering of glass, the screeching of twisting metal, the cracking of wood, and the crumbling of stone all combined with explosive thunder and a hollow echoing rang out, making Frisk fall off the bed. The noise seemed impossible to accurately describe beyond being loud enough to fill the whole house and giving off the impression of something breaking a little and something vanishing at the same time. And it was coming from somewhere below. Frisk heard a lot shouting and crashing as everyone else reacted to the noise in surprise, but they didn't waste time with confused questions. The child grabbed a familiar stick and old bandage from under their bed and ran out the door.

"My child? Did you hear that?" asked Toriel as they dashed past her down the stairs.

Unable to explain much to the large goat-like monster as they raced towards the front door, Frisk said, "Sorry, Mom. Basement."

"Wha—? We do not have a basement," she said, but Fisk didn't even slow.

The basement was a secret, the entrance around back and hidden by Asgore's gardening. No one else knew it existed, but Frisk and Sans didn't keep many secrets from each other. They both needed someone to confide in after everything that happened. The multiple timelines, the nightmares, the Saves, the Resets… Asriel and Chara… and the broken machine in the basement. Guilt and secrets were easier to bear when there was someone to share the burden. Frisk wasn't ready to tell everyone, but they could trust someone with the truth. And maybe someday he would trust them when Frisk told him no more Resets and that this timeline was the last.

Regardless, they knew how to get into Sans' hidden lab.

Flinging open the concealed door, they practically threw themselves down the stairs. As soon as their foot hit the purple tile, Frisk felt something wrong. It reminded them a little of the dark void where time held no meaning, where echoing memories of someone else's life rang in their mind, and where Frisk reached out to when they needed to load a Save or even attempt a Reset. This wasn't the void, but maybe… it was… leaking through a little? That was how it felt to them.

Sans wasn't here. There should be no reason to be surprised by his absence, especially with his shortcuts. But between the loud noise and the fact he left the sheet off the machine, Frisk knew he should be here. This was wrong. They could feel it in their gut. Sans was missing and they knew he needed help.

Somehow more concerning than Sans' absence was the figure next to the machine. Taller than the missing skeleton, the monster's face was white and cracked. Boney hands with holes in the palms floated at the ends of black sleeves with no visible arms, hands that he stared at intensely as if seeing them for the first time. Then he looked at one of the screens for the half-broken machine, reading the changing measurements briefly, before turning his gaze back towards his hands. Dressed in black over what might have once been a white turtleneck or might be bones melded together, he appeared to be caught in the middle of melting. He was partially liquid and dripping, looking a lot like the Amalgamates… or Undyne in that timeline filled with death and dust. High levels of Determination and monster biology didn't mix. He should be dying, but he wasn't.

And Frisk knew the monster. They didn't remember seeing him in most timelines. Only in a few rare instances did they hear even hints about the monster and only in one memory fragment of a Reset timeline did Frisk remember catching a glimpse of him. In Waterfall, in an empty room behind a door that normally didn't exist, they found him briefly before he vanished. Outside of time and space, erased as if he never existed, almost no one could properly remember him. No one except those grey echoes of monsters, a child whose memory extended past time to events that never happened, and the short skeleton who was too close to the machine when everything went wrong and yet too far away to vanish as well.

"Dr. W. D. Gaster," said Frisk carefully.

The monster jerked his head up at the sound, turning his cracked face towards the child. But he didn't vanish this time. He even managed to pull his melting form together a little more, making his shape a bit more distinctive.

"Did Sans fix the machine?" they continued.

He paused a moment, as if gradually growing aware on his surroundings and the situation in general. Then he shook his head slowly.

A voice that defied description responded. The sounds clashed against each other, wavering in and out of focus like a radio signal barely in range. Nothing that reached their ears seemed recognizable as words in any language Frisk had ever heard, even with all the humans they met after the monsters were freed. Somehow the sounds even gave off the impression of something visual in their mind, images of gesturing hands and symbols. And even if Frisk didn't know the strange and grating language the voice used, they understood the monster.

" _One of the more pacifist versions, I see._ _Forgive me. Existing in a single time and place without full omniscience is something that takes a moment to reacquaint myself with._ _I believe I know which timeline I am occupying now. No, the machine cannot be truly repaired and never will, little one_ ," he said. " _It might be best to describe it as… Sans broke it in a particularly unique configuration. It connected this laboratory so that I can interact with the world in a limited fashion, so that I might exist in a linear and coherent state. Similar to what occurred with the room we first met in, but more reliable and stable. It is really quite interesting if it was not the side effect._ "

As Frisk prepared to ask what side effect, they heard several more footsteps coming down the stairs. Knowing that there would be a lot of explanations involved regardless of who was there, they reluctantly turned around.

"WOWIE! WHY DIDN'T ANYONE TELL ME THERE WAS ALL THIS SCIENCE STUFF IN THE BASEMENT? …OR THAT WE EVEN _HAD_ A BASEMENT?"

"Oh…M-my goodness. I d-didn't have anything to d-do with this."

The entire household apparently decided to investigate the strange noise. The bipedal goat-like Toriel and Asgore were in the back, trying to avoid the ceiling. Asgore's horns tended to leaves scratches in buildings and rooms not built for him. The taller skeletal monster, Papyrus, and the blue fish-like monster with the eye patch, Undyne, were in the front of the group. They didn't even bother to hide their staring. And partially hiding behind her taller girlfriend, Alphys looked shocked, confused, and worried. The yellow lizard-like scientist probably could understand more about meaning of the machine across the room and the half-liquid monster than anyone else present.

" _Hello, Papyrus. It is good to see you again, even in these less-than-ideal circumstances_ ," said Gaster, his partially-melted face managing to shift into a smile.

Tilting his head slightly in confusion, he said, "I DON'T REMEMBER MEETING YOU BEFORE AND MY MEMORY IS NORMALLY SENSATIONAL. YOU ALSO SEEM RATHER MEMORABLE." He narrowed his eyes briefly before admitting, "…THOUGH SOMETIMES I DON'T KNOW WHAT I KNOW. YOU KNOW? REGARDLESS, YOU WILL UNDOUBTEDLY BE PLEASED TO KNOW THAT I, THE GREAT PAPYRUS, AM ALWAYS HAPPY TO MAKE NEW FRIENDS. SO WELCOME TO OUR MYSTERIOUS BASEMENT I DIDN'T EVEN KNOW ABOUT UNTIL NOW, STRANGE MONSTER."

Maybe it was just how his face was melting, but the smile on Gaster looked a little sadder than a moment before. He just gave the skeleton a small nod.

"Frisk, my child?" said Toriel, watching the unknown monster uneasily. "Do you know this person?"

They nodded and said, "Mom and everyone? This is Dr. W. D. Gaster, a scientific expert on space, time, Determination, and the Core. Gaster? These are all my friends and family. My mom, Toriel, and my dad, Asgore. Also known as the former Queen and the King of the Monsters. Undyne, Captain of the Royal Guard when everyone was in the Underground and probably the town police once we get everything sorted. Alphys, the former Royal Scientist and still really smart. And Papyrus already introduced himself."

They knew Gaster probably already knew everyone's names. Some he would have met before the accident and others he would have observed while scattered across time and space. But it was at least polite to do proper introductions for everyone. Not to mention that being scattered across space and time, simultaneously aware of everything that was, is, would be, and could have been, probably didn't offer many opportunities for socializing.

" _It is nice to properly greet all of you. And though returning to a linear, limited, and corporal state is a relief after so long,_ " he said, staring down at his hands with a half-melted expression of cautious hope before shifting to something more serious, " _the circumstances are less than ideal. The machine connected to the void between time enough to let me slip out at least partially, but the backlash caused undesired additional side effects._ "

"You mentioned that. What happened?" Frisk asked. Worry building up in their chest, they met his dark eye sockets firmly. "Where is Sans?"

" _The more productive question would be… when is he…_ "

Alphys, always quick on the uptake, started stammering in a panic. While Undyne tried to calm her girlfriend enough to get a solid word out of the reptilian monster, Frisk stared calmly at Gaster. They had grown experienced at judging emotions on very inhuman faces. Even with his perpetually-melting features and cracked skull, they could tell that he was upset about what happened. But he wasn't hopeless.

"Dr. Gaster, perhaps you could explain what is going on?" suggested Toriel, a slightly dangerous tone to her voice that Frisk considered to be her Queen Voice.

" _I can try to summarize the more important and immediate facts, Your Majesties. But if I may request Dr. Alphys' expert assistance, I would like to work as I speak. This matter is extremely time sensitive._ "

"M-me? B-but I… I c-can't…"

" _You are indeed smart enough for what I need. Besides_ ," he said gesturing at himself as his body dripped, " _solid hands are an advantage that I currently lack_."

Smiling at her, Undyne said, "Go for it, Alphys. My favorite nerd can handle whatever this Gaster guy needs to do. And if the kid trusts him, whatever he wants must be all right."

"BUT WHAT ABOUT MY BROTHER?" shouted Papyrus, focusing on the important part. "IS HE IN TROUBLE?"

"… _Yes, he is_."

And that sparked off a lot of loud questions from the gathered monsters. The voices clashed and melded with each other until none of the individual words were comprehensible. Frisk just waited patiently until there was a break in the noise.

"He's in the past, isn't he?"

Sliding to the side, Gaster revealed a slight wavering in the air behind him. It reminded them of the rippling effect of a heat wave above asphalt during the summer. The weird overlapping sensation of that dark void seemed to be concentrated near the odd sight. Frisk didn't know if anyone else could notice the void between time, but they could at least see the ripples.

" _You have always been a clever human child when you are on a kinder path. Yes, the backlash of the imperfectly-repaired machine tossed Sans into the past… and another timeline._ "

"Which timeline?" Frisk asked.

"Are you talking about time travel? Isn't that impossible?" asked Asgore. "I… Someone _tried_ to do it… But I can't quite remember."

As the large monster frowned in thought, Gaster muttered something to Alphys in his strange voice. Whatever he told her must have been some type of instructions because it prompted her to start poking around the innards of the machine.

" _Physically traveling through time to your own timeline's past is impossible. And mental time travel is only slightly more useful since most people cannot remember a previous timeline beyond vague déjà vu. Sans fell into a timeline that no longer ever happened and replaced the Sans that belonged there. He only possesses the memories of that timeline as long as he's there._ "

"Which timeline?" Frisk repeated, their worry growing worse.

"This is a lot to take in," said Asgore. "I'm uncertain how any of this happened, but I assume that you have a plan on how to retrieve Sans. Would I be right?"

"Gaster!" Frisk snapped, their voice louder and sharper than normal. They were generally a quiet child and only spoke when they felt it was important, but they had to know. "Which timeline? Which Reset?"

The half-liquid monster gave the child a solemn and tired smile so similar to the ones they'd seen from Sans. His perpetual grin could communicate a wide variety of emotions and Gaster's cracked face shared that trait.

" _You already know the answer to that, Frisk. He is waiting in judgment for the one emptying the Underground of monsters. And it is the timeline where he cannot dodge forever._ "

Frisk felt like the wind was knocked out of them. Even if they only remembered fragments of what happened before Resets, they remembered enough over time to know that Gaster was describing the worst version of events. One of their first runs through the Underground, somehow stopped near the end by something they couldn't remember, Frisk hated thinking about those events. Every decision made was the wrong one. They carved a path of dust and violence, committing genocide against the monsters.

And Sans was thrown back into that timeline with only the memories of Frisk at their worst, about to fight a battle he was doomed to lose.

"HEY, I SEE SOMETHING," shouted Papyrus, pointing towards the strange rippling in the air.

Whatever Alphys and Gaster were doing to the machine, it was affecting the unusual spot near the back wall. The wavering mirage-like thing had changed. Frisk could see colors and shapes, like they were staring out a window that was fogged over. And the longer they stared, the more the image came into focus.

It was the corridor before the throne room. In fact, the angle of the view seemed to be near the door to the throne room. They could see the golden stained glass windows casting their warm light across the place. Tall columns ran along either side of the hall and the tile floor was so smooth that Frisk half-expected to see a reflection in them.

And in the middle, appearing practically out of nowhere, was a short skeleton in a blue coat and comfortable slippers. Frisk almost smiled in relief at seeing Sans. But on the far side of the corridor was a sight that made them tighten their grip on the stick in their hand.

Brown-hair and dressed in a familiar blue-and-pink striped sweater, Frisk stared at a darker version of themselves.


	2. Chapter 2

Sans hid all hints of sorrow, loss, and fear, shoving it all to the back of his mind. He couldn't risk any sign of weakness. If the Human thought they had a chance, Sans wouldn't be able to frustrate them into giving up. He needed to maintain a strong front. All he could show them was bored indifference and anger. As long as he outwardly looked calm and confident, maybe the Human would believe they couldn't win for once.

Sans couldn't be certain the creature was actually human anymore. As they walked into the corridor, they still looked human-shaped. Their brown hair, blue-and-pink striped shirt, and dark shoes were all coated in dust. The gold locket around their neck and the sharp knife in their right hand were new, but the power in the objects suggested they belonged to another human at some point. Humans seemed to imbue power into their belongings over time, turning harmless objects into weapons and armor. But the Human's new objects were not the main point of interest. Sans stared at their face.

There was an emptiness in their eyes. Their constant serene smile felt blank with only the occasional glimpse of something that may have once been merciful and good before everything went wrong. Looking for hints of their thoughts was difficult because their face seemed empty of real emotions. And there was a darkness that clung to the Human, marking them as something far worse than any human or monster.

He could sense their LOVE and EXP even at a distance. Their Level of Violence and Execution Points were so high, fueled by every death they caused. It was like an aura of evil that he could feel, sending a shiver down his spine. The pain that they've inflicted on others… Their capacity to hurt others and distance themselves from that cruelty… It clung to them like a shadow of corruption, one he could practically see. The Human may look like a child, but they were more like a demonic force. It might even be more than just the LOVE and EXP causing that unnerving atmosphere that surrounded them. Honestly, everything about them was utterly terrifying.

The Human stopped a short distance away, staring at him with their creepy smile. Sans kept his hands in his pockets, trying to keep his posture casual and relaxed. He couldn't show any weakness. He couldn't. He couldn't give that child the satisfaction. Sans knew how to read facial expressions and could tell the Human had faced him over a dozen times, always failing. Stubbornness, frustration, and anticipation for an eventual victory hid in that smile. And yet there was still an emptiness that he couldn't quite put his phalange on.

Maybe they would give up in time. Maybe he could make them Reset. He couldn't remember properly, but Sans knew he'd done it before with whatever affected the timeline before the Human. If he could frustrate that anomaly in the past, maybe he could force this Human to stop too.

" **heya. you've been busy, huh? ... so, i've got a question for ya,** " he said evenly before closing his eyes in regret. " **do you think even the worst person can change...? that everyone can be a good person, if they just try?** "

Papyrus believed that. No matter what happened or who he encountered, Papyrus never doubted there was good in everyone. While Sans sunk into apathy and resignation, Papyrus remained optimistic and hopeful. Sans depended on his younger brother to be the one thing in his life that was good, the one thing that still made Sans try. He needed Papyrus to be hopeful, to be optimistic, and to believe there was still good in people.

But the Human used that faith and killed Papyrus.

As the Human took a step forward, Sans continued, " **heh heh heh heh... all right. well, here's a better question.** " He opened his eyes briefly again, but they were dark and completely lightless. " **do you wanna have a bad time?** " His eyes closed again as he tried to mentally prepare himself for what was about to happen. " **cause if you take another step forward...,** " he continued, giving the child a final dark look, " **you are REALLY not going to like what happens next.** "

Sans wasn't even surprised when they apparently took his words as a challenge. The smile widening just a little more, the Human took a step forward. The emptiness in their eyes somehow seemed more unnerving and the oppressive atmosphere from their presence seemed darker. He closed his eyes.

" **welp. sorry, old lady. this is why i never make promises.** "

She was probably dead anyway, just like everyone else. So he had nothing to hold him back. And no one left to lose. So he tugged their Soul out of their chest to start the fight.

* * *

Frisk cringed a little when they heard Toriel ask, "Wha…? What is going on? Is that you, Frisk?"

" _Yes and no_ ," said Gaster. He was still dripping as he and Alphys worked on the machine, but he looked a little sturdier. " _It is complicated and would take too long to fully explain. What you see is a glimpse of an earlier timeline. They are not precisely the same as the child who brought down the Barrier. They followed a different path_."

"Can they see or hear us?" asked Asgore.

"N-not yet," Alphys said as she rewired a section of the broken machine. "W-we're trying… Um, we're g-going to strengthen the c-connection… We're turning it into… into a portal."

"UH… THERE'S SOMETHING WRONG WITH MY BROTHER AND THE OTHER FRISK," said Papyrus, sounding mildly worried. "THEY SEEM RATHER… TENSE AND AGITATED."

Frisk stared at the mirage-like image. They shivered at the empty eyes and the cruel smile, knowing what lurked behind them. They felt so uncomfortable knowing that they were once the same person. And they knew what was about to happen.

"Can you go faster?" Frisk asked anxiously.

"Uh… Maybe?" said Alphys. "Why?"

Glancing briefly at the lizard-like scientist, they said, "Sans is in danger. That me isn't nice and I know what's about to happen next."

Toriel must have noticed something in their voice. Or perhaps she was guessing from what could be heard from Sans on the other side. The maternal monster stepped closer to Frisk with a concerned look on her face.

"What is about to happen, my child?"

"The same thing that happened to the other monsters there," they said, feeling sick to their stomach at the memory.

Frowning in confusion and maybe mild suspicion, Undyne asked, "Hey, punk… How do you know all—"

Frantic movements and loud noises erupted from the rippling portal-to-be, interrupting her question. Frisk flinched involuntarily at the blurry memory of that first brutal attack now performed right in front of them, one that took ages to learn how to dodge.

They deserved every hit.

* * *

Eyes still closed as he gathered his strength and resolve, Sans said flippantly, " **it's a beautiful day outside. birds are singing, flowers are blooming. on days like these, kids like you...,** " he said in a slowing and harsher voice before snapping his eyes open, the lights darkened by his cold fury, " **Should be burning in hell.** "

His left eye glowed, flashing blue and yellow as he wrapped the Human's Soul in blue magic and snapped out his arm. Shifting gravity on their Soul rapidly with sharp gestures, Sans sent them slamming them to the floor of the corridor. Then bones erupted, forcing the child to dodge for their life for a few seconds. And when they survived that, he summoned the Gaster Blasters. Huge animalistic-skull-like shapes appeared and fired intense blasts from their mouths, the sound distinct and powerful.

After several blasts, his conjured attacks dissolved. The Human was still standing, the psychotic smile in place, their eyes empty, and their cheeks just staring to flush with excitement and exertion. Sans tucked his hand back in his coat pocket, trying to maintain a casual air. Nothing annoyed and frustrated an opponent like fighting someone who didn't seem to care or worry about the battle.

The lights in his eyes returning, he remarked, " **huh. always wondered why people** **never use their strongest attack first.** "

The Human didn't say a word. With swift movements, their knife flashed through the air. The intent to kill combined with the power already bound to the weapon made it act more like a monster's attack, a sharp red streak appearing in the air where they swung. It held there for a fraction of a second before flying at the skeleton at a blinding speed.

And Sans sidestepped the slash.

" **what? you think i'm just gonna stand there and take it?** "

When a guy only possessed one HP and one defense, being able to dodge was essential. Even if other monsters didn't want or intend to harm him, accidents could happen. He might be lazy, but Sans knew how to dodge and had the reflexes to avoid even some of the fastest bullet attacks in the Underground.

But he knew he couldn't dodge forever.

Pushing that thought down along with the rest of his fears and sorrow, Sans called up a familiar bone pattern and sent it towards the Human. The child, their Soul glowing blue, moved through the bones with clear experience. Since Papyrus never even tried to fight them, the familiarity must be born from simply facing Sans repeatedly. They knew the patterns and the tricks to survive.

As Sans broke off the attack, the Human struck back almost before their turn began. Another vicious strike that he simply sidestepped.

" **our reports showed a massive anomaly in the time-space continuum. timelines jumping left and right, stopping and starting...** " he remarked casually.

Another bullet pattern of bone erupted, essentially a more ruthless version of his brother's repertoire. The Human fought gravity's pull on their blue Soul, throwing themselves through the smallest gaps.

Their retaliating slash was nearly blinding fast, forcing Sans to slide in his slippers. Their attacks didn't have much variety or imagination. And their turn only comprised of a single cut each time. Compared to what a monster could do, it looked rather plain. But it would be more than enough if they landed a blow.

" **until suddenly, everything ends** ," he continued as if there was no interruption to the flow of conversation.

Bones sprang up from the ground while the Human fought to keep above the threat. The serene smile never wavered. And as soon as they got a clear shot, their knife flashed through the air again. Sans slipped to the right and kept his own grin in place. But his eyes darkened.

" **heh heh heh… that's your fault, isn't it?** "

This time he summoned up the Gaster Blasters. The wide beams took up a large section of the corridor, leaving less room to dodge. But they avoided his attack just like Sans slid past the retaliating strike.

Some of his frustration edging into his voice, Sans said, " **you can't understand how this feels.** "

Bone attack patterns. The Human dodged. They slashed their knife. Sans leaned to the right. They were settling into a rhythm.

" **knowing that one day, without any warning... it's all going to be reset.** "

More bones flying through the air while the child moved expertly though the tiny gaps with split-second timing. The blade flashed through the air and Sans barely moved to avoid it.

Remembering better days, before his life became so complicated and out of his control, he shrugged and admitted, " **look. i gave up trying to go back a long time ago.** "

Again. Bones, Human dodges, knife slashes, and sidestep.

" **and getting to the surface doesn't really appeal anymore, either.** "

Once again. Bone attacks, dodge, knife, sidestep.

" **cause even if we do...** " he said, his eyes growing even darker as his mind followed that hopeless path to its conclusion, " **we'll just end up back here without any memory of it, right?** "

The two of them were going through the motions. They couldn't land a hit on him and if he had nicked them yet, it wasn't enough to really notice.

" **to be blunt... it makes it kind of hard to give it my all.** "

But he had to try. This time, it mattered. He couldn't win, but he couldn't just stand by and let things continue as they were. That's why things had gotten as bad as they were. It was why his brother was gone. He'd given up on life.

Bones, dodge, slash, sidestep.

" **...or is that just a poor excuse for being lazy...? hell if i know.** "

Both of them were fast with their attacks. And while the Human was forced to keep moving to keep their Soul intact, Sans kept his movements to a minimum. He dodged just enough to stay alive and no more. He needed to conserve his strength, which was running out faster than he liked. This was a marathon, not a sprint.

…Papyrus would have liked the jogging metaphor.

" **all i know is... seeing what comes next... i can't afford not to care anymore."**

This time, he summoned up the Gaster Blasters and fired away.

* * *

"What is he doing?" yelled Toriel as Sans ended his first attack. "He could have killed you. Them. The other Frisk."

"How's he doing that?" Undyne said, sounding rather impressed. "I didn't know the lazy guy had it in him."

And then most of the group flinched as the alternate Frisk tried to slice Sans in half. None of them remembered seeing the child do anything close to being violent towards someone. Even Undyne's attempt to train them mostly involved dodging and defensive moves. Frisk knew the monsters would soon be very disillusioned. Everyone would see how far the child could fall.

" _Sans only remembers the events of that timeline_ ," reminded Gaster, fingers moving surprisingly fast as he worked on rearranging the wires and tubing. " _He remembers only the child of that timeline, not the Frisk that you know._ "

"Don't be mad at him. He's trying to stop a murderer," Frisk admitted reluctantly.

The shocked and confused responses from their friends and family were mostly covered up by San's next attack. Frisk kept their eyes on the portal-to-be. They didn't want to meet the faces of their loved ones. Not now.

Her voice gentle and nonjudgmental, Toriel asked, "Frisk, my child?"

"I… It would take too long to explain everything right now, Mom," they said. "But I made mistakes. I did terrible things before I got it right. And in that timeline, I… killed… _everyone_."

Frisk blinked back the tears trying to form. They still didn't look at anything other than Sans' fight. As guilty and worried as it made them, they still preferred watching the bone attack patterns to seeing everyone's faces.

"Every monster in the Ruins, in Snowdin, in Waterfall, in Hotlands… Mom, P-papyrus, Undyne, M-mettaton, and…," they tried to continue, their voice wavering. "And I c-couldn't stop. Alphys snuck a few monsters to safety before I could find her, but I k-killed everyone else. When I reached New Home, Sans tried to stop me. He _is_ trying to stop me."

"I… I DON'T _FEEL_ DEAD," said Papyrus. "ARE YOU QUITE CERTAIN THAT WAS NOT A BAD DREAM? I KNOW THAT YOU AND MY BROTHER ARE PRONE TO THEM."

"It was another timeline, not this one," Alphys reminded in a neutral tone, most of her focus on the machine. "It won't r-really affect us here, so it could have happened."

"And how does Frisk remember?" asked Undyne. "And why is Sans talking about anomaly things and blaming them for time stuff?"

" _Because the child has the ability to Save and Reset, to affect the timeline to an extent. Their Determination, higher than any subject ever encountered, allows them to mentally return to an earlier point with no effect on their body and cause different outcomes_ ," explained Gaster simply. He clearly had no time for secrets or tact. His hands kept moving with his repairs and alterations as he continued to speak. " _The reason why Determination in high enough quantities affects the timeline is still uncertain, but it is a verified fact. This machine is powered by Determination, even as it performs an action it was not built for originally_."

"Save? Reset?" asked Asgore. "That sounds familiar…"

Alphys muttered, "I'm not even certain understand how half of this design operates. And w-where would someone get enough Determination to build this?"

" _The same place you extracted it for your own experiments, Dr. Alphys_."

Frisk knew they would have to explain about Saves and Resets eventually. They wouldn't be able to avoid it, especially with how tangled up that power was with what was happening to Sans. But their worries about that would have to wait. There were far higher stakes and more immediate concerns.

They asked, "How long until you're done with the machine? We don't have much time. Sans needs to get out of there."

Focus on saving their friend. Don't look at everyone else. Frisk didn't know if they could handle it if everyone hated them or if everyone was horrified by what they once were. And if their friends and family became scared, it would hurt so much. Frisk knew they would deserve those reactions, but they couldn't deal with that kind of misery just yet. They couldn't think about it. They needed to stay Determined. Even if Gaster hadn't said it yet, Frisk knew that they would need their Determination to save Sans.

And Sans was running out of time. Frisk could see that. While it went against everything the child knew about science and was probably due to magic instead, the skeleton was starting to sweat from his efforts.

* * *

His Gaster Blasters dissolved as his attack ended, leaving Sans to catch his breath briefly. Even with minimal physical movements, the magical strain was starting to affect him. Sweat formed on his skull from exertion. That was bad. Any sign of weakness would be noticed by the Human. He hadn't hit his limits yet, but it was time to change tactics.

" **ugh... that being said... you, uh, really like swinging that thing around, huh?** "

The Human's expression never even twitched. Their creepy smile, their skin pale with dust, and their flushed cheeks remained exactly the same. Sans briefly wondered how many times they'd heard this speech.

He wondered if they ever accepted the offer.

" **...listen. i know you didn't answer me before, but... somewhere in there. i can feel it. there's a glimmer of a good person inside of you. the memory of someone who once wanted to do the right thing. someone who, in another time, might have even been... a friend?** " He winked briefly as he pleaded, " **c'mon, buddy.** " Sans opened both of his eyes again and stared at the child with his constant grin. " **do you remember me?** "

Sans almost stopped, feeling a sense of familiarity so strong it almost hurt. Maybe that glimmer was more than a glimmer because he could almost feel it. As if he'd lived through a better life, one that didn't end in so much heartache and sorrow. Were they faint memories of a previous timeline?

He shook off the déjà vu reluctantly. He couldn't think about it. He couldn't let himself be distracted. None of it mattered unless the Human was stopped.

Sans closed his eyes and said gently, " **please, if you're listening...** " He opened his eyes again, meeting their unnerving gaze. " **let's forget all of this, ok? just lay down your weapon and…** " he said before closing his eyes briefly tiredly, " **well, my job will be a lot easier.** "

Sans opened his eyes as he waited for the child's response. He didn't truly believe they would choose Mercy after all of the deaths they caused, but he tried. It would be easier to kill them quickly without a struggle if it worked. And if they didn't accept, Sans was still able to recover his strength a little during the break in action.

The Human, closer to him that they were through most of the fight, didn't surprise Sans. The knife flashed through the air, barely missing the dodging skeleton.

" **welp, it was worth a shot,** " he said before his eyes darkened. " **guess you like doing things the hard way, huh?** "

Deciding it was time to raise the bar, Sans shifted to his more intense and magic-costly strategies. He filled the entire corridor with summoned bones and Gaster Blasters. Then doing the same thing he did to access his "shortcuts," he started teleporting the Human randomly around the room. He dumped them anywhere and everywhere, never giving them a chance to adapt to the new dangers. He teleported the child rapidly and alternated their Soul between red and blue. He kept them off-balanced and disoriented. And Sans finally started landing blows.

His attack strength was as weak as his HP and defense, but he could still cause plenty of damage. Rather than a large chunk of HP being lost per hit, it whittled away their life for every fraction of a second. It accumulated quickly and slipped past their defense. And as a final touch, his attacks paid back a little Karmic Retribution. The greater their LOVE and EXP, the greater their sins against those they encountered, the more it leeched away at them slowly. Sans was finally hitting the Human.

He just needed to keep going. He just needed to keep it up a little longer. He just needed to outlast the Human until they gave up.

* * *

"He's going to _Spare_ the punk? I thought they killed all of us!" shouted Undyne.

"It's a trick. If I accepted, Sans would have attacked and killed me," Frisk said numbly. "In that timeline, I… I did the same thing to Papyrus. He tr-tried to Spare me and I killed him anyway." They were quiet a moment as they stared through the gradually-stabilizing portal as the knife flashed through the air. "I'm sorry… I'm so sorry…"

A boney hand rested on their head gently and Papyrus said, "I KNOW YOU ARE. AND YOU'RE NOT THE SAME HUMAN AS THAT ONE. YOU'RE MUCH NICER AND COOLER THAN THEM, MOSTLY BECAUSE THIS YOU HAS A REALLY COOL AND AMAZING FRIEND: _ME_!"

That managed to produce the smallest smile. Of course he would be the first to forgive them. Frisk knew he wasn't one to hold a grudge and didn't have a mean bone in his body. It was comforting to know that some things never change, though they weren't certain they deserved such comfort.

"He is right, my child," said Toriel. "You are not that person, even if you might have once become them in another time. We know who you are here and now and we still love you. That has not changed."

"Yeah, punk," Undyne said, reaching over to noogie them a little. "We just prefer the wimpy version who freed us to that creepy brat."

They felt warmed by the support of their friends and family. Even when Sans broke out the more impressive and dangerous attack patterns, Frisk didn't feel quite as guilt-stricken. But their worry remained.

"When you fix the portal, how are we going to get Sans through before he gets hurt?" asked Frisk.

" _It will not be us who helps him, little one. You will be the one who must go through and retrieve him_ ," Gaster said.

* * *

Another slash of the knife became a red streak in midair, hate and killing intent giving the attack greater power. Even with the strain of all the magic he was using, Sans could still slide to the side while looking completely casual. As long as his efforts seemed casual and effortless, maybe it would frustrate the Human.

" **sounds strange, but before all this i was secretly hoping we could be friends** " he admitted. **"i always thought the anomaly was doing this cause they were unhappy. and when they got what they wanted, they would stop all this.** "

He threw another bone attack pattern at the child, stronger and faster than before. The Human moved through the hazards while flinching when they didn't dodge quite fast enough. They kept the empty-eyed grin on their face.

As they sliced towards the skeleton this time, he thought he briefly saw a flash of green and yellow. It startled Sans enough that he almost didn't move out of the way in time. But he dismissed it as a trick of the eye socket and focused more on his opponent.

" **and maybe all they needed was... i dunno. some good food, some bad laughs, some nice friends.** "

His eye flashed and his left hand shot out sharply. This time Sans wrapped blue magic around the Human's Soul and started redirecting gravity's direction for them. Every surface they impacted, he summoned bone protrusions to stab at them if they weren't fast enough.

The instant Sans was forced to end his turn, the Human bounced back to their feet and swung that blade again. Another small movement and the attack slipped by.

" **but that's ridiculous, right?** " he said as his eyes darkened." **yeah, you're the type of person who won't EVER be happy.** "

More bones and Gaster Blasters filled the air. Sans sent the child teleporting randomly around the corridor again. The less predictable the attacks, the more frustrating it would be for the Human and the more likely they would give up.

He couldn't keep it up for long though. These attacks took more energy. And when his bones and Gaster Blasters dissolved away, the Human slashed at him again and forced him to slide out of the way.

* * *

"No," said Toriel. "You cannot send my child into danger. I will not allow it."

That made Frisk turn and look. She was using her Queen Voice on him, but Gaster didn't even slow with his rewiring. He looked a little less goopy, like he was growing more used to being a physical presence again. He was definitely wearing a white turtleneck under his black robe and his face looked more like a cracked skull than a melting mask. But he was not intimidated by the tall figure glaring at him.

" _I know that no parent wants their child in harm's way when they can't protect them. Trust me when I say I know that fear_ ," he assured her. " _But this is the only option available. Sans will not reach the portal on his own without being killed. The child is too fast and he does not have the defense or HP to survive a hit. And he is using up his magic quickly. He will need help to escape._ "

"Then I'll go grab him," said Undyne, stepping forward and summoning a spear. "It'll be great to knock that brat down to size.

Frisk shook their head desperately. They knew that while Undyne managed to slow them down in that darker timeline, it took fatally high levels of Determination. And that was when they were weaker. If she went in, she would die.

* * *

Eyes still dark with emotion, he continued. " **you'll keep consuming timelines over and over,** " San's eyes brightened and he said, " **until... well. hey.** " The skeletal monster shrugged with a wink and said, " **take it from me, kid. someday... you gotta learn when to QUIT.** "

Another attack of bones flew through the air, blinding fast and intense. He threw out the most complicated patterns he knew. The air whistled with the speeds involved. And yet even that was not enough to do more than clip the child a few times.

He thought he saw that flash of green and yellow as the Human sliced at him again. But Sans didn't let himself be distracted this time as he moved to the side.

" **and that day's TODAY.** "

More bones and Gaster Blasters. Another difficult dodging attempt by the Human. And another flash of the blade that Sans managed to avoid.

* * *

" _Frisk is the only one who can go through the portal. We are reconfiguring this machine to perform a function it was never designed for. Unlike Sans, they will not replace their other self. They will remain separate from the child in that timeline. But if anyone else tried to go through, they would only have the memories of that timeline and would not recall their purpose in going. And since the rest of you are dead there… It would not be pleasant. Frisk is the only one whose memories can remain intact across different times._ "

Not to mention that Frisk knew anyone else would be quickly killed. They couldn't let any of their family or friends be hurt like that. Not when they had the power to stop it. They needed to Save everyone and that meant they would take the risk.

"Don't worry, Mom. I'm strong enough to survive anything and I'll be right back. And I have to go," Frisk said firmly. "Sans needs me."

"You sure? He's doing pretty good so far," said Undyne, raising a fist in the air. "Get them, Sans! Let your passions burn and pound your enemy into the ground!"

"UH… ACTUALLY, I THINK HE MIGHT BE IN TROUBLE," Papyrus said, sounding worried. "HE NEEDS TO REST AND I DON'T THINK THE OTHER FRISK WANTS TO STOP."

* * *

" **cause... y'see... all this fighting is really tiring me out,** " Sans admitted.

That was a bit of an understatement. Sans did his best to hide it, but he was running out of energy fast. He was using far more magic than he normally attempted. But he needed to keep going like before. For once, he couldn't give up.

Another round of intense and rapid bone attacks surrounded the Human and forced them to dodge wildly around the corridor. The child didn't even look slightly tired. Considering how sweat was running down skull and how his bones were beginning to ache, it didn't seem fair.

Of course, a cruel and murderous child having control over the flow of time wasn't fair either.

He definitely saw a momentary flicker of green and yellow when he slipped past the knife this time. There was something weird going on, but he had to keep going.

Closing his eyes briefly, he said, " **and if you keep pushing me...** " Sans winked. " **then i'll be forced to use my special attack.** "

He had a plan. A desperate plan, but the only one he could use. He brought out the Gaster Blasters again, sending the child dodging. And when they tried to retaliate, Sans still moved out of the way with minimal effort.

" **yeah, my special attack. sound familiar? well, get ready. cause after the next move, i'm going to use it. so, if you don't want to see it, now would be a good time to die.** "

Sans sent them teleporting around the corridor again, filling the room with bones and Gaster Blasters. But even though he tried to keep it random and impossible to predict, the Human slipped through alive. And the instant he released them, the child struck back. Sans barely dodged the slash that time.

He was at the end of his rope. Monsters needed magic to survive. Their bodies were mostly composed of the stuff. While certainly not the most common stories, there were a few of them from the war with humanity of monsters desperately pouring too much magic into their attacks and not leaving enough for their bodies to easily endure. Monsters approaching that point could Fall Down, barely alive and not likely to recover.

Sans didn't know if he was at risk for that fate, but he wasn't feeling great at the moment.

* * *

Glancing back towards the soon-to-be-fixed portal, Frisk realized what stage of the fight they'd reached and began to panic internally. Sans was running out of time. They remembered what happened soon. Even with their blurry and fragmented memories of Resets, they knew what was quickly approaching.

"Can you go faster?" asked Frisk, not wanting to make Alphys anxious and yet scared they wouldn't finish in time.

"W-we're trying," she said. "This isn't exactly easy."

" _It is taking longer than I was expecting_ ," said Gaster, his strange voice sounding worried as his hands practically flew as he worked. " _You may need to move quickly the moment we finish._ " His voice paused briefly though his hands never slowed. " _Frisk, while you are in that other timeline, you will not be able to Save or Reset properly. You do not belong there, not as a separate entity from the child of that timeline, so you cannot use that power while there. You will be on your own._ "

Their friends and family still looked completely confused, but Frisk understood what they were telling them. They wouldn't have any second chances. The thought scared them, but Frisk also felt filled with Determination.

The stick and the old bandage they now slapped on their wrist might not be the best options for what was about to happen, but they didn't have time to run back upstairs for the other objects they collected on their journey through the Underground. They would have to depend on what they first brought into the Ruins.

* * *

The Human didn't seem intimidated by the idea of his upcoming special attack. The closest thing they showed to concern for what Sans might try next was to stuff an uncooked package of instant noodles in their mouth and smile their creepy empty smile at him.

" **well, here goes nothing...** " said Sans as he summoned up all of his remaining magic that he could. He gave the child a mocking wink. " **are you ready?** " Then, his eyes darkening with all the rage, sorrow, and desperation he felt, Sans said, " **survive THIS and i'll show you my special attack!** "

Sans didn't let himself hesitate or doubt his decision. Bones erupted from every surface as the Human tried to dash through increasingly narrow gaps. The bones moved around and sprouted without much warning, making the child bob and weave to protect their Soul. They had to practically race along the entire corridor as the bones closed in on all sides. Blue magic wrapped around their Soul as Sans yanked them around, trying to beat the murderous child down.

They killed everyone. They killed the lady behind the door. They killed Undyne. They killed _Papyrus_. He couldn't let them go forward. He had to make them Reset. He had to.

He teleported them into the path of a few Gaster Blasters. Again. And again. And yet again. Every time they moved out of the way, he sent them into the path of another attack. But they wouldn't die.

Keep going. He had to keep going. He couldn't give up. Not this time.

He summoned up more Gaster Blasters than he ever attempted before and fired rapidly. The light was nearly blinding as the room filled with the intense blasts. He could feel the floor vibrate under his feet from the attack. And even if the speed and pure power should have wiped the Human out of existence, they still managed to survive.

They had to Reset. They had to. They had to die and Reset. He needed them to go back and fix this.

Gripping their Soul in blue magic, Sans jerked his hand and slammed them against a wall. And another. And the ceiling. And the wall again. And the floor. Eye flashing blue and yellow, Sans kept rapidly shifting gravity on the Soul.

Please die. Please Reset. Please just die and Reset everything. Please give up.

His frantic and desperate movements began to slow as he started gasping for breath. Sans kept trying to push on, to keep attacking. But he couldn't. He was exhausted. His bones ached and his limbs felt impossibly heavy. He tried. He tried to keep going. But he'd used too much magic and couldn't do it. There was nothing left.

Gasping and struggling for breath, he said as casually as he could manage, " **all right. that's it. it's time for my special attack. are you ready?** " His eyes darkening, he said, " **here goes nothing.** "

He didn't move, just standing there with his eyes closed. There was not any other option left. He didn't have the strength to try anything else. He was just so _tired_. He'd thrown everything he could at the Human. This was his final plan for when everything else failed.

Opening his eyes, Sans said, " **yep. that's right. it's literally nothing. and it's not going to be anything, either.** " He didn't mean to close his eyes again, but keeping them open was such a struggle. " **heh heh heh... ya get it? i know i can't beat you. one of your turns... you're just gonna kill me. so, uh. i've decided... it's not gonna BE your turn. ever.** "

He managed to get his eyes open again to stare at the child. He even managed another mocking wink.

" **i'm just gonna keep having MY turn until you give up.** " Sans' eyes darkened again as he declared, " **even if it means we have to stand here until the end of time.** " Then, with false friendliness, his eyes brightened back to normal and he asked, " **capiche?** "

He could do this. He could outwait them. He could keep his turn going indefinitely. Just keep his grin steady, hide his hands in his pocket to conceal how they shook with exhaustion, and don't show any weakness.

The Human looked mildly annoyed. But they didn't seem ready to give up yet. The child's Determination kept them going.

" **you'll get bored here. if you haven't gotten bored already, i mean.** " he said before his eyes darkening. " **and then, you'll finally quit.** " Sans waited a moment, trying to recover any hint of energy before he continued. " **i know your type. you're, uh, very determined, aren't you?** "

His eyes closed again briefly. He was so tired. Everything ached. He just wanted to rest. But he couldn't let them keep going.

" **you'll never give up, even if there's, uh... absolutely NO benefit to persevering whatsoever. if i can make that clear.** " Sans' eyes slipped closed again without him wanting them to. " **no matter what, you'll just keep going.** " He pried them back open. " **not out of any desire for good or evil... but just because you think you can. and because you** _ **can**_ **... you** _ **have to**_ **.** "

He was so tired. Sans couldn't let them see how badly the fight wore him out. Even if they never touched him with that knife, trying to kill the child and not die in the process took its toll.

* * *

" _No! We're so close. Connect that now, Dr. Alphys_."

"What's going on?" asked Asgore.

"Sans can't fight anymore," Frisk said, wanting nothing more than to run forward. "He's almost out of time."

" _It won't happen. I will not allow it. We have to finish_ _ **now**_."

* * *

" **but now, you've reached the end.** " Sans closed his eyes briefly and said, " **there is nothing left for you now.** " He was running out of things to say. He was too tired to think. He looked towards the side and muttered, " **so, uh, in my personal opinion...** " He forced himself to meet the Human's gaze one last time. " **the most "determined" thing you can do here?** "

Sans regretted looking towards the child. The emptiness in their eyes was still there, but there was a certain smugness to their smile now. They were noticing his weakness. Sans looked away.

" **is to, uh, completely give up. and...** " He yawned, unable to stop himself. But he tried to ignore it and continued, " **do literally anything else.** "

Laziness wasn't to blame for how hard it was keeping his eyes open. Exhaustion wrapped around him, body and Soul. He wanted to sleep. No, it was more than that. He needed rest desperately.

But he couldn't do it. He had to stay awake. Sans knew if he could be patient, the Human would grow bored. He clung to that small hope, desperate for it to be true since he'd thought he'd lost all hope a long time ago. He just needed to stay awake. He just needed to hold out.

His eyes kept trying to close. Everything ached. Unconsciousness kept pulling at him. Sans resisted as best he could. He fought to stay awake.

The Human would give up soon. They had to. They would Reset soon. He just needed to hold out a little longer. This was his only chance to make things right again.

When did his eyes close? He didn't remember doing that. Maybe just for a moment…

* * *

" _Go now!_ "

Frisk ran.

* * *

The whistle of the blade through the air was the only warning he got, but it was enough to jolt Sans out of his accidental nap. Fear for his life gave him just enough energy to jerk to the right, avoiding the sneak attack. The Human was right in front of him with their creepy smile, knife in hand.

Trying to shrug off the close call, he said, " **heh, didja really think you would be abl—** "

The knife swung and something hit his chest, knocking him back and cutting off his words.

Sans flinched, expecting pain to follow. But there was nothing except a pressure of something touching his chest and the feeling of… green magic?

The skeleton opened his eyes and saw the top of someone's head that was a little shorter than him. One arm was outstretched in front of them, holding a stick and creating a shield of green magic. Undyne could do the same thing with her spears, though she was usually too hot-headed to bother. The other hand was reaching back. It rested against his chest, pushing him behind them. They were breathing heavily, probably from running to get between him and the blade in time.

Human. Brown hair and a blue-and-pink striped sweater. But no dust coated them, no unnerving and shadowy aura surrounded them, and he couldn't detect any LOVE or EXP. He wasn't certain what to make of the situation.

And when he looked towards the Human on the far side of the green shield, they seemed equally stunned by the turn of events. Their smile was gone… and did their striped sweater turn green and yellow?

The child with the stick turned their head a little, letting him catch a glimpse of their face. A face that he knew all too well and yet could barely recognize. Their expression was calm. Not blank or empty, but calm. But Sans saw something else. Relief. A lot of it. The child was relieved to see him. They cared. They looked like the murderous one, but Sans could tell they were polar opposites. He could also catch a glimpse of their floating Soul in front of them, green as the shield they were somehow creating.

" **i know humans don't have as much variety as monsters** ," Sans said quietly, " **but this is** _ **twin**_ **-sane**."

They smiled at his words. Not a creepy smile, but one on the verge of chuckling.

"Sorry I _cut_ it so close."

The murderous child, on the other hand, seemed to be over their initial shock. They regained their own smile, something more predatory than before.

"Greetings, Frisk," the Human said, speaking for the first time in the entire battle.

Turning back towards the pale child with the flushed cheeks who no longer looked quite the same as before, they nodded in response.

"Chara."


	3. Chapter 3

Having his mind and awareness scattered across time and space, gaining knowledge of all possible timelines and events in every corner of the Underground, nearly drove him mad. No one was meant to hold that much knowledge simultaneously. It took him time to regain anything resembling sanity, to be able to make sense of everything he could observe in the void. But eventually he could follow how Flowey and later Frisk used their Determination in order to Save and Reset. He even managed to create a temporary room to manifest himself in for a moment before being yanked back.

But now all of it was gone. He was limited, linear, and back in the world. He could interact with the world again for the first time in he didn't know how long, but he lost most of the omniscience. He couldn't even take a moment to appreciate existing again, couldn't let it sink in properly yet. He was too worried. He didn't know for certain what the future held. So when Gaster saw Sans in danger, he did not know if they would be fast enough to stop the human child of that timeline. He didn't know if it would work, but he chose to believe it would.

Frisk, at least the pacifist one, was the one who Saved everyone. He had faith in the human child. Gaster knew they performed horrible actions in other timelines that the child still regretted, but Gaster was also weighed down by his own sins and mistakes. He knew Frisk would do their best to save the skeleton. He knew they would try. But when Frisk dove through the portal just as the knife moved, Gaster nearly lost control of his physical shape and melted from worry.

But then he saw the child shove themselves in front of Sans and throw up a shield to block the blade. Relief washed over Gaster. It worked. Sans survived.

Placing a hand on Papyrus' shoulder, Gaster reassured, " _They reached Sans in time. Your brother is unharmed._ "

The skeleton glanced at him briefly and gave a nod of appreciation. But no recognition. That was the hardest part of his return. Seeing so many people that he once knew who no longer remembered. The King and Queen hired him before their children's deaths. Dr. Alphys worked for him for a time, thankfully late to the lab the day of the accident. But it was worse knowing that Papyrus had no idea who he was.

That was a thought for another time, though. The young humans were facing each other and one was being overlaid by the echoing and distorted memory of a dead and soulless fallen child. And if King Asgore and Toriel were too far away to see the change in features, they still heard what Frisk called them.

"Chara?" whispered Toriel. "But that's…"

"I thought that was another Frisk," Undyne said.

" _It is both of them_ ," said Gaster. " _It is complicated_."

He knew there would be more explanations in the future. Frisk and Sans would have to explain a lot when this was over. None of those explanations would be pleasant for them, but they were long overdue.

The pair would just have to make it back first.

* * *

Frisk allowed themselves a moment of relief and happiness at their success. They only managed it at the last moment, but they did it. They shoved themselves in front of Sans and shifted their Soul to green in time to block the fatal strike. They couldn't run away while their Soul was green, but they could at least defend.

Unfortunately, Frisk still had a problem. Armed with a knife and more aggression that was healthy for anyone, their past mistakes stood in front of the pair. But they no longer looked like Frisk's mirror image. Someone else was in control and the pale skin, flushed cheeks, and the green-and-yellow sweater all reflected that. Something else was draped over the original features, like a second skin. An angry and dead child was now strong enough to control the body.

Frisk wasn't facing themselves at that moment. They were facing Chara.

" **chara, huh? wasn't that the king's human kid?** " mumbled Sans.

"Surprised?" they said with an unnerving smile. "Not as surprised as I am to see Frisk while they are still here." Chara tapped the side of their head. "How did you manage to be in two places at once?"

"It's complicated," said Frisk. "We don't belong here. You don't have to fight us. Just let me get Sans home."

Tilting their head, Chara said, "You think you can steal that EXP from me? That power is mine. I will not let you take it. But if you insist, I can kill you too."

Frisk wasn't surprised. Even if they didn't quite remember this encounter completely and wasn't sure what happened next, they weren't surprised. It would be too much to hope for. Chara was too far gone at this point in the timeline. They would have to take the hard way.

Getting Sans back through the portal to safety was their number one priority though. With their hand on his chest, Frisk could feel him swaying on his feet and trembling in exhaustion. They knew Sans wouldn't be able to dodge or fight anymore. Not without help. He could barely stay awake. If they didn't get Sans somewhere safe, Chara would just finish what they started.

"Hang on tight, Sans," said Frisk. "I'll get you out of here."

" **and the kid with the knife?** "

"I'll stop them. They won't go any further." Frisk glanced over their shoulder at him and asked, "Trust me?"

" **not sure.** "

Frisk didn't blame him. He didn't remember them as anything other than a mass murderer. And even if he was friends with them and liked them, Frisk wasn't certain Sans really trusted them in the proper timeline. Not completely. Trust would mean believing there would never be another Reset and hope was scary after so long.

But Sans grabbed their shoulders to steady himself as asked. And that was close enough to trust for now.

"Your move, Frisk," said Chara. "Let us see what you can do with your stick. Try to make it interesting when I kill you both."

They didn't even think of choosing to Fight. Frisk always preferred to Act. They chose to Talk. Besides, the words seemed vaguely familiar even as Frisk began to speak.

"I know why you're doing this. I know what led you to make all these choices."

"Talking? Do you plan to try Sparing me? At least try to be more of a challenge than the comedian's brother," Chara said before dashing to the side.

They clearly intended to move around Frisk's shield, but spending time around Undyne meant the child's reflexes were sharp. Keeping Sans behind them, Frisk twisted and blocked the vicious slash with the green shield. Compared to a barrage from Undyne at her most dangerous, Chara's attack was nothing.

"You were miserable on the surface," continued Frisk. "Any family that you had no longer cared for you. Maybe they never did. Every human you ever knew betrayed your trust. Some were particularly bad, pretending to care or acting like they would help you only to turn out just as terrible and cruel in the end. They left you only seeing the worst in everyone."

Even as they spoke familiar words, their thoughts raced over possibilities. Frisk knew Chara was too close for the pair to escape. They needed some space. They needed to force Chara back and regain some mobility. They grabbed Sans's shirt tightly with their free hand and concentrated.

 _Yellow_. Anime and lab coats. Shy and low self-esteem. Technology. Heat and steam. Stardom and entertainment. Confident and flashy.

As Chara swung the knife through the air, Frisk's Soul shifted to yellow and fired. The shots blocked the attack and knocked Chara back a few steps. While it certainly stung to be hit by them and would destroy monsters' bullets, they wouldn't affect their HP. And it knocked the smile off Chara's face.

"How are you doing that?" asked the murderous child.

"Alphys and Mettaton. You never took the time to know them and experience yellow magic. You never got to know any of them. You never learned anything in the Underground except how to kill. But I understand why," Frisk said as they slowly backed up, pushing Sans a few unsteady steps back as well.

" **you've got a few nice tricks, kid** ," he mumbled. " **ya got a plan too?** "

Frisk didn't respond to him. They were focusing on the other child.

"When you were at your lowest point, when humanity hurt you for the last time and you couldn't stand it any longer, you climbed Mt. Ebott. You went to the mountain with all those stories about it. You gave up and climbed that mountain, hoping to disappear forever."

A wordless shout erupted as Chara slashed, but Frisk moved to the left while pulling Sans along. Their yellow Soul fired rapidly, hitting the red glow from the cut and Chara both. Frisk kept knocking them further away and trying to edge Sans down the corridor.

"Just shut up," snapped Chara. "You do not know anything."

" **pretty chatty now, aren't ya?** " Sans said. " **i** **liked it better when you kept quiet. so** _ **cut**_ **it out.** "

Frisk frowned in worry. The words sounded like him, but everything else felt wrong. He seemed to be depending on them to keep upright. Frisk could feel him wobbling behind them, clinging to the child's shoulders with shaking hands. And his voice was so exhausted, it _hurt_. He wouldn't be able to keep moving like this, even with Frisk dragging him along.

"When you get the chance, head to the end of the corridor," they said quietly. "There's a portal near the door to the throne room. You need to go through it."

" **where's it go?** "

"Safety. Home."

"You are going nowhere," snarled Chara.

They broke into a run, weaving in an attempt to dodge any further shots. But Frisk was already switching tactics.

 _Purple_. Strange priorities, obsession with money, and tangled webs. The smell of baking pastries, tea, and old cobwebs. Spiders.

Lines like the threads of a web spread across the floor as Frisk's Soul turned purple. When Chara drew near, Frisk tightened their grip on Sans' shirt and switched lines. Almost like a jump, their Soul could be yanked between the lines instantly and could move normally along them. It limited their mobility a little, but switching lines could cover a lot distance quickly and dodge instantly. As Chara tried to land a blow, Frisk hopped between different lines while yanking the exhausted skeleton along like the tail of a kite.

Frisk might not be particularly close to Muffet compared to some of the other monsters, but she knew how to spin a tidy web. And her purple magic had some uses.

* * *

"Ngaaaah! Show that other human how you defeated me! Chat, cherish, and pet the enemy into submission! Mercy them until they _beg_ for mercy!"

While Undyne cheered and supported their friend enthusiastically, Toriel and Asgre seemed to have more complicated thoughts on the situation. Gaster didn't blame them. Their dead child was in front of them again, but not as they seemed in life. Chara's memory and spirit had been corrupted until they controlled that timeline's Frisk. And now they were trying to kill Toriel and Asgore's newest adopted child. It couldn't be easy for the pair.

Gaster and Papyrus, while concerned for Frisk, focused mostly on Sans. He could see Sans clinging to the child's shoulders for balance and to keep up with Frisk's maneuvers. He saw the skeleton stumble slightly as he struggled to stay on his feet. He could see how Sans' expression seemed drained of life and energy. Gaster could recognize the signs of someone on the verge of collapse and he could tell that Papyrus saw those same signs.

"ARE YOU SURE I CAN'T GO IN THERE AND GET SANS? THE OTHER FRISK IS KEEPING THEM TOO BUSY TO ESCAPE."

"I w-wouldn't try it. I think parts of this machine don't completely exist anymore and th-there's a noise I really don't trust. I'm not certain h-how it's working or honestly how s-safe it is," said Alphys.

" _It is safe enough for Frisk and Sans to return, but you must not go through. It wouldn't be safe for you. No matter what happens, no one else can go through that portal,_ " Gaster said firmly. " _You must trust Frisk. That is all we can do._ "

"I TRUST FRISK. THEY ARE ALMOST AS AMAZING AS ME," assured Papyrus. "I'M STILL WORRIED THOUGH."

Gaster didn't blame him. Even with Papyrus' boundless optimism and faith in the inherent good of people, concern for his family took priority. It was easier to risk your own life for what you believed in than to risk someone else's.

* * *

Sans still wasn't completely certain what was happening. He was smart and could probably figure out more if he tried, but he was too tired to concentrate enough for that. He didn't know much about Frisk compared to the murderous child and he could only gather a few clues about what they were talking about, but he could tell they were Determined. Specifically, they were Determined to keep him alive for some reason. Maybe his feeling that that they could have been friends in a different timeline wasn't completely farfetched.

His more immediate concern was the overwhelming, aching exhaustion that tried to engulf him. Surprise and shock provided him with a little energy when Frisk first appeared, but that was gone now. Of all the things he ever imagined happening, being dragged around the corridor while clinging to the child for stability wasn't one of them. He could barely stand on his feet. And when Frisk switched to using purple magic on their Soul, being yanked around to dodge Chara, Sans nearly stumbled to the ground.

A portal. Frisk said there was a portal he was supposed to go through. He still didn't know where it was supposed to lead and he was too tired to think about it. But he could tell that neither of them would be able to get anywhere while Chara tried to slice the pair apart.

"They're getting angrier," said Frisk. "This might get tricky. But we can probably get away from them anyway."

"Or maybe I could load my Save and try killing the pest again without having to deal with you," Chara said with a sharp-edged smile. Then they frowned in confusion. "What?"

"That power? Only the person with the most Determination in the Underground can Save and Reset," said Frisk calmly. "Flowey lost that power when you arrived. And even if I can't use it in this timeline, I have more Determination and can keep you from trying it either."

" **so no time shenanigans on either side** ," Sans mumbled, fighting to keep his eyes open.

"Then I will have to stop holding back. No more games," said Chara.

The murderous child dashed forward again and Frisk's purple-engulfed Soul started yanking the pair around again. And while Chara previously only slashed a single time for each attack, they extended it to a series of rapid cuts that proved to be difficult to dodge.

* * *

Frisk knew there was only one solution to the current problem. Chara's attack pattern had become more intense and elaborate than before. And while Frisk could dodge anything they could try, Sans couldn't. Not at this point.

They would have to split up. Frisk could distract and keep Chara at bay. If they could keep Chara busy, Sans could make a break for the portal. He would be safer that way and Frisk would be able to maneuver better.

They just wished they could remember how this turned out.

Letting their Soul yank their body between the purple lines, Frisk managed to get Sans over to a column. The child moved him so he was braced on the architecture instead. They barely had time to make sure he regained his balance before Chara tried to land a hit.

 _Green_. Strong, hot-blooded, and fearless. Sharp spears and shields. The smell of fish and burning pasta.

The shield formed just in time to block several quick slashes. Chara's empty smile was back. But just as the violent child tried to get around the defense, Frisk switched their Soul to yellow and knocked Chara flying back with their rapid fire.

The Act they chose this time was Distract. Marching forward, Frisk's yellow-enshrouded Soul kept firing. They made certain that all of Chara's focus was on them. It would seem the fight was reaching a whole new level.

* * *

While Sans could certainly understand the child's logic in leaving him behind and he certainly felt steadier braced on the unmoving column rather than the dodging kid, the idea of him making a run for the portal was a joke. And not even a good joke.

His legs were shaking and weak. His eyes kept trying to drop closed. He felt like his bones were coated in thick mud, weighing him down and making every movement an impossible effort. Walking the rest of the distance down the corridor seemed as likely as him growing to the same height as his family. It just wasn't happening.

He could see the two human children dashing around, weaving around the columns and sliding across the tile. Chara's knife was flashing through the air at a nearly blinding speed. They were no longer confining themselves to a single cut per attack, unleashing a chaotic storm of them. And Frisk kept dodging and blocking with impossible ease, their Soul shifting between a variety of colors. As good as Chara was at avoiding Sans' attacks, Frisk made them look like an amateur. They never swung their stick as a weapon and never got hit.

He couldn't stay put. He needed to move. Sans knew he needed to try. If he stayed, Chara would eventually kill him. Or he would pass out.

Sans focused on the next closest column. All he needed to do was make it there. Concentrate on making it that far and then he could worry about the next part. One step at a time.

The moment he pulled away from any form of support, Sans knew it was a mistake. He only managed a few wobbly steps before his legs gave out completely. And while he caught himself on his hands and knees, Sans realized he wasn't going any further.

It was important to know when to give up. Sometimes it was the only way to maintain a shred of sanity when nothing in your life mattered, when none of your actions mattered. Sans closed his eyes, too weary to care. Frisk could clearly handle the murderous child and he didn't have the energy to worry any longer. He couldn't do anymore. There was nothing left anyway. Now was the time to give up. He should just lie down completely and just let go.

"SANS, YOU LAZYBONES! GET UP! THIS IS NO TIME FOR A NAP!"

The voice, loud and unmistakable, cut through the noise of battle and practically yanked on Sans' Soul. His head snapped up and his eyes opened. He shouldn't raise his hopes, shouldn't let himself consider the idea. He knew it wasn't possible. The scarf fragment in his jacket pocket was all the proof he needed. But Sans knew that voice.

He finally spotted what must be the portal. There was a slight wavering in the air near the doorway. And he could see through it like a window. What he saw on the other side nearly broke him.

Papyrus. Alive and unharmed. Papyrus, his brother, was right there. Sans could barely breathe.

The taller skeleton seemed to be trying to jump through the portal after him. Undyne was holding him back, both arms wrapped around his body. Alphys clung to his ankle, adding her meager strength to keep him in place. And behind Papyrus, a dark shape that Sans couldn't quite make out also seemed to be keeping him from coming through.

Sans still might not know everything that was happening, but he didn't care. His brother was right in front of him. Papyrus was alive. That was enough.

Shaking with the effort, Sans started pushing himself back upright. If his younger brother was on the other side of the portal, then Sans would get there. One way or another, he would reach Papyrus. He might not have the humans' levels of Determination, but Sans would manage it anyway.

* * *

Purple magic wrapped around their Soul, the lines reforming along the tile floor. Frisk's Soul jumped between the glowing lines rapidly, yanking their body along behind it. They kept moving, dancing between Chara's strikes without much difficulty. Frisk knew how to dodge anything by that point. Chara's battles were generally fast and brutal, so they never learned to avoid hits the same way. Chara never developed the agility and maneuverability to match them.

The only way Chara could survive Undyne and Sans was by memorizing the pattern rather than learning the skills to adapt to them. Frisk couldn't beat them offensively, but they could beat Chara when it came to defense.

Distraction was key. Frisk would not Fight the child, no matter their crimes. They refused to kill. Never again. But Frisk could Act. They chose to Distract. And nothing could keep Chara's attention like the possibility of killing someone.

 _Yellow_. Frisk fired a handful of shots at Chara. The pale child dodged some of the hits, but most managed to knock them back a few steps. Chara's smile seemed a little more strained now. They were growing frustrated.

A few rapid knife slashes were sent towards Frisk as red arcs flying through the air. Each one was shot down by the yellow magic engulfing their Soul. Frisk didn't even have to dodge this time. They just stood there with a calm expression.

"Why will you not fight back? Those shots do not even touch my HP. Use that stupid stick already," snapped Chara.

Another series of rapid cuts were sent towards Frisk. They lifted their stick as their Soul shifted to green. The shield flew up to block the strikes. And the instant the attack stopped, Frisk let the magic fade and their Soul returned to red. That would make them seem more vulnerable and a more appealing target. Distraction was key.

This time, Chara's numerous slashes came faster. They ran around Frisk, sending the red arcs at a variety of angles to make the strikes more difficult to dodge. Frisk didn't bother calling any form of magic. They sent their Soul between the attacks with practiced movements. Slipping through the gaps was effortless on their part. Frisk did the same thing they did to survive the Underground. They wove between the threats.

"Did you never learn anything? Above or below. Kill or be killed. Humans or monster, they are the same," continued Chara. "In the end, none of those things matter. Power is what I need. I will have more EXP and LOVE. I will be strong enough to do whatever I wish. And you are in my way."

They raced around the corridor, practically bouncing off the columns as they started sending slashing cuts towards Frisk. Chara sent dozens of the strikes from all angles, every swipe of the blade sharp and ruthless. Frisk moved equally fast as they dodged. It reminded them of trying to avoid raindrops in a thunderstorm, though a lot more dangerous. And unlike in a storm, they were never hit.

"You are taking away what is important to me," said Chara, still swinging their knife in a flurry of attacks. "You are taking away my potential EXP, interfering with my fights. So I will take something of yours."

Dozens of swings of that blade filled the air with red streaks. Frisk could barely believe how many directions the strikes were coming from. The child's Soul was yanking their body everywhere.

Then Frisk noticed that not all the attacks were aimed at them. One red arc from the knife soared past Frisk towards a skeleton struggling to stand.

" _Sans!_ "

* * *

He'd barely regained his footing before he heard a desperate shout of his name. Sans managed to turn slightly and caught a glimpse of red, but all other thoughts were immediately driven out by an explosion of pain.

The impact knocked him off his feet and drove the breath out of his body, shock and pain leaving his eyelights as pinpricks. The pain was sharp and focused mostly on a long cut from his right shoulder to his left hip, though it was quickly spreading. After a moment of breathless shock, Sans' hand pressed against the painful wound and it started to sink in. He was dying.

His grin turned to more of a resigned grimace as his breathing fell out of any rhythm, leaving Sans gasping. He knew this would happen. He came into this fight knowing the murderous Human would kill him. He could feel his body trying to collapse apart. He knew he would die like this, in this corridor at the blade of that child and too exhausted to care anymore. He didn't even have the strength now to walk away.

" **you ruined… my favorite… shirt** ," he said quietly between gasps. " **you're definitely… evil.** "

There was more shouting. He heard his name a few times, but he couldn't make out most of the words. He couldn't even identify their voices for certain. It took all his concentration to hold himself together even a few seconds longer. Sans could barely think about the voices over the pain of his body trying to fall apart.

Then one voice rose above all the others.

* * *

For a brief moment, Gaster truly believed Sans would make it. He'd responded to Papyrus' cries. He'd climbed back to his feet, his expression stubborn. Gaster thought the short skeleton would be able to reach the portal.

Then, among Chara's storm of slashes, a single red arc of hate-fueled energy flew in a different direction than the rest. And when Sans turned at the sound of Frisk's warning, it cut along his chest and knocked him back to the floor. Gaster almost felt like the strike hit him instead, slicing right through his unstable body.

Not Sans. Not now. Not when he was so close.

Horrified and shocked shouts erupted from everyone. Alphys released her grip on Papyrus' leg, her hands flying to her mouth in surprise. Undyne seemed to be wrestling with warring impulses to keep restraining the taller skeleton and jumping through the portal herself. Asgore laid a comforting hand on his ex-wife's shoulder while they struggled with the reality before them.

And Papyrus seemed to be particularly traumatized. Gaster could feel him shaking beneath his grip. Tears were already forming and his voice was quiet. Too quiet for Gaster to understand the words. Papyrus was _never_ quiet. From when he was a tiny baby bones, Papyrus was loud and outgoing. A quiet Papyrus was just wrong.

Of course, Papyrus just saw his brother with a single HP struck down right in front of him and he was powerless to do anything. Gaster shared that pain. And there was nothing he could say to comfort Papyrus and no one understood why Gaster hurt just as badly. No one remembered. No one remembered the truth, even as he watched in grief as Sans struggled to hold on.

Gaster felt like he was melting apart again. He'd failed Sans. He came so close to seeing the bright young skeleton again, to having both of them back after so long, only to lose him. He never wanted his return to reality to come at the cost of Sans' life.

This was his fault. If Sans had just let him go and left that accursed machine behind, none of this would have happened. If it wasn't for Gaster being trapped in the void and Sans wanting to pull him back, he would have been safe.

"NO, NO, NO!" shouted Papyrus suddenly, sobs shaking his boney frame as he still tried to make a break through the portal. "SANS! P…PLEASE BE ALL RIGHT!"

" _I'm sorry. I'm so sorry…_ "

"SANS, TH-THIS ISN'T FUNNY!"

* * *

Even with all the pain, exhaustion, resignation to his fate, and what little willpower he possessed focused on keeping in one piece for even a few seconds longer, the voice reached deep down and pulled up a desperate thought.

Please look away, Papyrus. Please don't watch. Sans couldn't let this be his baby brother's last memory of him. He was dying and nothing could change that, but Sans didn't want to hurt him like this.

Losing Papyrus hurt so much. He couldn't cause that same pain to his little brother.

He couldn't turn back around to look at the portal. He didn't have the strength. Sans could barely hold himself together. He pulled his hand away from his chest, looked briefly at the red smear on it, and then pressed his hand back against the cut. He could feel his bones starting to crumble a little.

" **don't look, papyrus** ," he mumbled, not even sure his voice was audible.

He caught a glimpse of Frisk's face down the corridor. They looked horrified and desperate. But he also saw Determination.

Sans managed a weak chuckle. Poor kid. They tried so hard to save him. He honestly believed that in some other timeline, the two of them were friends. Probably on the other side of that portal where his brother was alive.

Maybe they would at least stop Chara. Maybe they wouldn't feel too guilty. And maybe they would take care of Papyrus.

His eyes slid shut and he stopped fighting the inevitable. It hurt, everything falling apart. But mostly it felt like falling into darkness.

But as he slipped under, Sans was hit with the sensation of motion to his crumpling body… and blue magic latching onto his fading Soul…

**Notes for the Chapter:**

> Please don't kill me for the cliffhanger. What can I say? The story is getting longer than expected. But hopefully four chapters will be enough to finish.


	4. Chapter 4

**Notes for the Chapter:**

> So there's a little good news/bad news going on right now. The bad news is that this story won't be finished in this chapter. The good news is that means you'll get a longer story. I hope you enjoy it.
> 
> Though I will say this much. Would it kill Toby Fox to tell us exactly why Sans' death scene was the only one to show a splash of red? Out of all the characters, why is he the one that ends up like that? Wouldn't one of the skeletons be the one least likely to cause a red stain like that? Couldn't Toby at least identify the liquid? That would have made things so much easier for us…

Frisk felt like the wind was kicked out of them.

No. Please, no.

Even when they tried their hardest, they'd failed him. The hit landed.

A long cut across Sans' chest oozed a thick red liquid. They weren't certain if it was blood, liquid Determination, ketchup, or something else entirely. The only good thing was that the appearance of the substance seemed to stun Chara nearly as much as it did Frisk. Sans was the first person they fought that bled and that was enough to make anyone hesitate.

And that was all that Frisk needed. Frisk didn't hesitate; not with these stakes. They dashed forward and knocked Chara off their feet with the stick. The pale child hit the floor hard. That would buy Frisk a few seconds.

Frisk turned back. They saw that his grin was more of a grimace and that Sans' body was growing unstable. He was dying and nothing could change that; neither science nor magic could fix him. But Frisk had a crazy idea, a lot of experience Saving people, and plenty of Determination.

Jokes, secrets, and shortcuts. Grease and ketchup. Grins and puns. Apparent laziness, hidden brilliance, and rekindled hope.

It didn't work in the past when Frisk tried it on themselves. But as Sans closed his eyes and started to crumble, they focused on _blue_ with all their heart and soul. And rather than trying to wrap the magic around their own Soul, they sent the power towards the fragile one in the failing skeletal body.

A human Soul could last quite a while after the body died. A boss monster's Soul could last a few seconds after the loss of their body. A normal monster's Soul vanished as soon as their body dissolved away. But for a few precious seconds, there was still enough material for the blue magic to grasp.

With hope and Determination, Frisk took his magic-engulfed Soul and shifted gravity on him. The result was Sans' Soul and his crumbling body being flung sideways. And just as he seemed to be more dust than solid, he flew through the portal.

* * *

The shift was so abrupt. One second, he was sinking into darkness. Into unconsciousness. Into oblivion. He barely existed and was barely aware. The next second, the pain vanished and his body felt solid. Stable. Alive and intact.

Sans managed a surprised gasp, barely having the chance to realize he was flying through the air. Then his back hit something, causing him and the obstacle to collapse into a pile of limbs and bones. His head spun from the impact and a flood of memories washed over him.

Good food, bad jokes, a few laughs… A child who never harmed, but met each challenge with a more soft-hearted approach and befriended everyone they encountered… The Barrier shattering… Sunsets, clouds, and real stars… A home on the surface with his brother and his friends… Trying to fix the stupid machine for the millionth time… The machine malfunctioning and reacting unexpectedly, something exploding out and swallowing him…

As the memories of his life in this timeline reasserted themselves and leaving his mind as a jumbled mess, Sans realized he was on someone's lap, leaning back against a sturdy chest while desperate arms clutched him close. His grin relaxed into a genuine one. He didn't even have to look and was perfectly content not to bother. He would always recognize Papyrus, the taller skeleton sitting on the floor and hugging his brother against his ribs.

" **hey, bro** ," he said quietly, not bothering to open his eyes yet.

Sans didn't want to move, enjoying the solid embrace holding him tight. The memory of Papyrus being killed still seemed far too real… and yet not real.

" _Thank goodness you're all right. You're both all right…_ ," whispered an unusual and yet familiar voice before being drowned out by a louder one.

"SANS, DON'T YOU DARE SCARE ME LIKE THAT AGAIN! YOU'RE NOT HURT ANYMORE, RIGHT? PLEASE BE OKAY NOW! AND YOU'RE NEVER ALLOWED TO ALMOST DIE WHILE I CAN'T EVEN HELP YOU OR GET NEAR YOU OR DO ANYTHING! NEVER, EVER, EVER AGAIN! I C-CAN'T… DON'T… SANS, I…I…"

The way Papyrus' voice cracked and trailed off like that hurt. Sans never wanted that. As he prepared to apologize for scaring his younger brother so badly and to ask who else was around, a scream pierced the air. Sans' eyes flew open and he caught sight of the portal. And through it, he saw the corridor.

Things had grown worse very quickly.

* * *

"It worked," Frisk whispered, their body slumping as they blinking back tears of relief.

The portal led to a different timeline, one where none of this ever happened. And while here Sans was out of magic and dying from his injury, that never happened at home. Back in that timeline, he was alive and whole. They'd just needed to get him back there before he was gone.

Frisk had somehow managed several miracles at once. They used blue magic, they used magic on someone else, and they saved their friend before it was too late. Granted, they didn't mean to throw Sans directly into his brother like that. But the blue magic evaporated as soon as he crossed the portal and his body returned to normal, though the momentum kept him going. Still, it worked out in the end.

They saw Papyrus hug his brother tight, his posture declaring pure relief. Frisk relaxed a little and smiled at the scene.

And someone instantly pounced on that momentary mistake.

"Raaahh!" snarled Chara just as pain exploded in Frisk's left shoulder.

They screamed as they fell to the ground. They couldn't help it. Even after so many fights and dying so many times, it still hurt. Just like they couldn't help the tears that formed.

Chara ripped the knife back out just as painfully, undoubtedly smiling at the shouts of alarm and worry that came from the portal. There seemed to be a stiffness to their expressions and movements that didn't exist before. But that didn't stop them from placing a foot on Frisk's back and staring towards the portal.

"They may have stolen away my prize, but they opened up an entirely new world," Chara said. "I can kill all of you again. So much EXP just waiting. Should I start by finishing off the slippery comedian finally? Kill his brother in front of him again? The weak cowards who called themselves my parents? Or I could just go after whoever is the slowest at escaping. So many possibilities."

Frisk gritted their teeth against the pain. Then they summoned up yellow magic around their Soul while rolling out from under Chara's foot, sliding across the smooth tile while their shoulder practically screamed at them. Frisk shoved themselves upright and fired, knocking the other child further away from the portal.

Practically gaping in shock, Chara said, "Wha… That is impossible. I hit you with my strongest weapon. You should be dead."

"You hit my body with the knife, not my Soul with magic," Frisk said while panting, clutching their shoulder briefly and trying to ignore the sticky blood staining their sweater. "And I'm not a monster. Just because you really want to kill me doesn't mean it's enough to make it happen. Besides, you don't want this. You never did. Not really."

"You know _nothing_ ," snarled Chara, racing forward again with their stained knife.

* * *

Seeing the kid hit the floor with the blade buried in their shoulder sparked an instant reaction from him. This wasn't about a promise to a lady behind a door to protect any human that came through. He was long past that. This was completely and utterly Sans.

He struggled, trying to pull free of Papyrus' desperate grip when only a second before he was perfectly happy to stay still. The previous physical exhaustion and depleted magic no longer held him back. Both afflictions evaporated along with the pain of dying the moment he was flung through the portal, though the mental exhaustion remained. The only thing really stopping Sans from giving Chara a repeat performance was his brother's refusal to let go.

The murderous child was monologuing. He heard Toriel crying. Undyne stood to the right, spear in hand. And Papyrus still held on.

One of the traits that both brothers shared was a protectiveness for those they loved, which currently translated into Papyrus refusing to loosen his grip. While Sans appreciated the sentiment, his brother needed to release him _now_. Even the psychotic dead child of the King and Queen couldn't just stab Frisk and get away with it, especially after almost killing him too. And apparently killing everyone in the Underground. He had to act.

" **give me five minutes to wipe that smug grin off their face and i'll come right back** ," said Sans, still trying to pry himself free as his eyes darkened. " **i'll even bring frisk back with me.** "

"NOPE," Papyrus said, somehow tightening his grip even more. "YOU'RE STAYING RIGHT HERE."

" _In that timeline, you are_ _ **dead**_ ," said the unusual and familiar voice firmly, coming from behind Sans and Papyrus. " _You were dying and you cannot go back without risking that fate. And then Frisk's efforts would be in vain. None of us can cross that portal, Sans_."

A hand reached down, grabbing Sans' shoulder. It was skeletal in basic appearance with a hole through the palm, but it did not seem quite solid. There was a soft and liquid-like quality to it, like a plastic bag filled with pudding.

Sans knew that voice and he knew that hand, though neither were exactly right. But he couldn't turn around to face him. He was afraid to admit the possibility. Not after all this time. If he was wrong, the dashed hopes would be too painful to bear.

But before he was forced to confront the idea that it might be real, he saw Frisk roll away from Chara. With a calm and yet pained expression, they bounced back to their feet and fired yellow magic. And rather than making their escape, Frisk continued the Fight.

"I cannot watch this," Toriel whispered.

"Frisk," called Asgore. "What are you doing? Please come back."

Watching Frisk's expression carefully, Sans said, " **the kid isn't done yet**. **they've still got to stop chara**. **they still have to give the child mercy.** "

He shook his head tiredly, his mental exhaustion still in place even if his physical fatigue was gone. He should have known they would pull something like this. Not that it would have changed anything if he _had_ known.

" **can't see how this'll work. chara doesn't want mercy. but they never know when to give up**."

" _And it would seem that Frisk helped you rediscover that trait in yourself. Your apathy seems to have stayed in the Underground. I certainly prefer you with hope, life, and drive. Watching you drowning in despair and resignation for so long was difficult to bear._ "

He couldn't deny it again. He couldn't mistake that voice for anyone else, even with the changes to it. Sans would not forget the impression of visual images of hands and shapes in the strange words, though everyone else forgot. Even with how the sounds now grated against each other in a way that almost made him cringe and how it wavered in and out of focus, he knew the voice. Sans finally turned away from the portal and looked behind him at the shape looming over the two brothers protectively.

He saw Papyrus glancing between the dodging Frisk and the skeleton in his grip, his expression worried. And behind him, one hand each on the brothers' shoulders, was a dark figure with a pale face. Half-melted, his face cracked, and barely recognizable as the monster Sans remembered, it was still him. It really was. It worked.

Almost unable to breathe, Sans whispered, " **da…** _**gaster**."_

* * *

"I know," said Frisk. "I know you went to the mountain, angry and scared. You went to the mountain hoping to disappear, to make everything stop. But you fell. Still angry and afraid of everything the world threw at you, you fell into the Underground."

Clearly growing frustrated and failing to block out the words, Chara flew into a violent frenzy. The blade flashed frantically through the air. But Frisk wouldn't be caught by surprise again. Even with pain slowing them down, the child dodged every strike.

They knew what to do. They knew what to say. Frisk knew what came next.

They _remembered_ what happened next.

"And still angry and even more afraid than before, you met someone. He acted nice and friendly, but you weren't sure if you could trust him. No one was ever nice to you without it being a trick."

"I was right," snapped Chara, slashing rapidly at them. "Asriel betrayed me. We could have done it. We could have killed the humans and broke the Barrier. He was too weak. He betrayed me like everyone else."

Their shoulder throbbed in pain as Frisk twisted past some of the attacks and fired at others. But that didn't matter. The important part was that they were listening.

"And then you met M— _Toriel_ ," Frisk continued. "She loved you instantly and just wanted to keep you safe and happy. But you were still scared and angry with the world. Anything that good couldn't be real."

"She never loved me. She replaced me with the next human to fall. And the next. And the next. She will replace you too."

Frantic swings of the knife forced Frisk to duck and roll, the child biting back a yelp of pain at the movement. They wrapped their Soul in green magic. Maybe not moving too much would be better. Frisk threw up a shield in preparation.

"You were so scared and so angry. You couldn't understand. Then everything went wrong."

* * *

The situation may have still been grave, but Gaster couldn't help feeling happy and relieved in that moment. His cracked face broke into a smile at the smaller skeleton's voice. Sans was alive. Sans knew him. And he heard what Sans nearly called him before he corrected himself, likely knowing that now was not the time for the explanations everyone would demand. But even that fragment of a word was enough to warm Gaster's Soul, making him feel better than he had in a long time.

"YOU KNOW HIM? WOWIE! MY BROTHER KNOWS EVERYONE!" shouted Papyrus.

" _Yes, Sans has known me for a long time_ ," Gaster said quietly. He squeezed both of their shoulders, thankful for having the pair safe and with him. Turning his gaze back to the portal, he continued, " _Do you know what your friend intends to accomplish now? They were only supposed to return you home._ "

Sans didn't immediately respond, simply staring at Gaster for a moment longer. Even with his perpetual grin for all circumstances, Gaster knew this one was completely honest. The wonder and joy at seeing someone he never expected to find again… You could not fake such a look. It took him a few moments to shake off his stunned happiness enough to return to the matter at hand.

" **they're gonna do what they always do. or at least they're trying**." Sans closed his eyes briefly, making Papyrus shift his grip slightly as he looked at his brother in concern. " **the kid is the eternal optimist who believes they can save anyone if they don't give up. and the other one just wants to kill everyone, nothing even slowing them down**."

" _What happens when an unstoppable force_ ," Gaster said, looking at Chara, " _meets an immovable object?_ " he finished as he turned towards Frisk with their shield.

"W-well," said Aphys anxiously, "it generally isn't good. Something has to give. Something usually b-breaks."

* * *

Frisk blocked another flurry of deadly blade swipes, the green magic keeping them safe. Chara's grin looked completely fake and very strained by now. They couldn't hide their frustration, fury, and hatred. But Frisk could also catch glimpses of what was beneath the surface. And that's what was far more important.

"Eventually you heard a voice in the back of your mind, feeding into your fears and anger. It gave you an idea, one that you never should have listened to. But when you made the mistake of listening, death followed."

"Shut up!" shouted Chara.

The attack was fast and frantic. But they didn't put any thought into their strikes this time. Chara just swung wildly as the slashes crashed against the shield. They were beyond rational fighting. They were getting sloppy.

"In the end, you killed. You killed out of fear at first. Fear became anger and anger led you to give in more to that voice. You tried to distance yourself from those who were dying by your hand. You tried to pretend you didn't care. You pretended it didn't matter as long as you reached your goal. And when it got really bad, you thought you had to keep going anyway. You'd gone so far, so how could you possibly stop?"

"Shut up, shut up, shut up!" shouted Chara, stabbing at the shield stubbornly. "You do not know anything about me."

"But it isn't too late. You can still stop. What's ahead of you isn't worth the cost," Frisk continued, both their voice and shield steady in the face of that onslaught. "You don't want this. You don't have to do this. You made a lot of mistakes and hurt so many people. But you can try to make up for what's happened."

"Graaah!"

They slashed viciously, trying to break through the shield since they couldn't get around it. Chara's movements seemed particularly frantic and disorganized. Frisk didn't even budge, letting the furious child lash out at them uselessly.

"You can do the right thing. You can make a different choice," Frisk said gently. "No more dust. No more blood. No more death. You don't have to listen to that voice or that fear and anger that you've been drowning in for so long. Just let it go and take back control of your life. I know you can be better than this."

"How can you be this stupid?" yelled Chara, not even bothering to attack this time. "This _is_ what I want. Why would I stop when I am so close? Why would anything you say make a difference? I know the consequences for my actions. Do you? Why do you think I would ever want to change anything?"

Even with what they remembered, Frisk was nervous about what they were about to do. There was certainly a risk and they wouldn't get a second change. No Saves and no Resets. It would be final.

Toriel was definitely going to ground them if they survived. Not that any of Frisk's friends would be happy about this stunt… except maybe Undyne, who might be impressed… No, she would be mad too.

"While maybe once you might have been able to be a better person even without your Soul, Chara, that's not going to happen now. There's too much LOVE and EXP burying any compassion away," Frisk said. "I'm sorry. I can't Save you in this timeline, Chara."

Their smile dropping briefly in confusion, they asked, "Then what have you been doing this entire fight?"

Dropping their shield, their stick, and the green magic around their Soul, Frisk chose to offer Mercy. They opened their arms, offering a hug and leaving themselves completely vulnerable. There was always a danger when they tried to Spare someone who didn't want it.

"I wasn't talking to you earlier, Chara."

* * *

When Frisk started using their shield again, Sans actually started to relax a little. They seemed to be on top of the situation. Even if they were still trying to talk sense into the crazy murderer, Frisk was keeping Chara at bay and didn't seem to be in dangerous of being hurt worse. As long as the kid stayed on their toes, they could keep up with the killer. A few of the other monster were even beginning to relax again and trust that Frisk could talk their way out of the situation like they always did, though the red stain on their sweater meant no one could completely banish all their concerns.

Sans felt his brother's grip loosen a little, apparently realizing he wasn't going to make a break for it. But Papyrus didn't climb to his feet. He stayed in place while Gaster kept a gentle hold on both brothers.

Frisk would be all right. They would be fine. Just because the kid hadn't come back yet didn't mean anything bad would happen to them. If anyone could handle Chara, it would be another human. And if anyone could resolve this peacefully, it would be Frisk. He just needed to have a little faith in the kid.

And what faith Sans had in Frisk's survival abruptly evaporated when their shield vanished and they dropped their stick. Papyrus' hold on him tightened just as Sans tried to launch himself back to his feet.

They left themselves completely vulnerable as they tried to Spare their opponent. And that struck a chord with his strange not-quite-memory and knowledge from the other timeline, reminding him that Papyrus tried the exact same thing with the exact same child and died for it. What was the kid thinking?

He remembered what they said before. No Saves or Resets. If they died, Frisk wouldn't be able to reverse it. They would stay dead.

" **move, kid,** _ **move**_ ," Sans urged, wishing he could grab them with his magic and yank them out of danger.

He couldn't see Chara's expression, but he saw them twitch. Then they moved like lightning. The knife appeared against Frisk's throat and everyone yelled in horror.

"Let me at them," shouted Undyne. She threw a magic spear that dissolved as it hit the portal. "Leave our kid alone."

Frisk didn't move. They didn't even try to pull away. Instead, they smiled calmly at the murderous child.

"Help me, please," Frisk called.

Sans felt his Soul ache as it sank in exactly how helpless all of them were at that moment. None of them could save the child. None of them could go to Frisk or stop Chara. After they did so much for all monsters, after they risked their life just today to save him, no one could do anything to save them in return. Frisk called for help, but none of them could answer no matter how much they wanted to.

But somebody came.

* * *

Frisk didn't panic when the knife was pressed against their throat, the sharp edge uncomfortable and almost breaking the skin. And they couldn't even listen to their friends and family screaming out to them. They focused on Chara's expression, the way they seemed to be struggling internally against some force. Frisk also saw beneath that. They saw what lay under the shell of Chara's control.

"Help me, please," they called.

Frisk saw their face twitch at the words. Then Determination flared up from deep within the child. The knife fell to the floor with a _clank_ and arms wrapped around Frisk in a frantic hug that made the cut in their shoulder burn with pain. But they returned the embrace.

The appearance of Chara _shattered_ ; the pale skin, rosy cheeks, and the green-and-yellow sweater vanished from sight as the soulless echo of the dead child was banished. And Frisk was left holding a sobbing and shaking child.

"I'm sorry… I'm so sorry… I—I don't… Why did I… I'm sorry," sobbed the dust-covered child, sounding so young and horrified. "I just… So many… P-please… no more… no more… Why? Why did I listen… I'm sorry… I can't…"

"I know," they said gently. "But you did good just now. You saved me. You'll be all right. We can fix this. We can make things right again."

Ignoring the pain in their shoulder, Frisk patted their back and made soothing sounds as the dust-covered child cried over what they'd done. Frisk knew how much it hurt when the fear and anger vanished and realization sank in. Frisk knew how hard it was to bear the weight of all that guilt hitting at once. Frisk knew how awful it felt once Chara's EXP and LOVE vanished, leaving all those sins and nothing to provide any distance from the crimes. Frisk knew exactly what they were going through.

After all, Frisk remembered. They remembered being the dust-covered child shaking and sobbing about their actions. Frisk held their past self, trying to comfort them just as they were comforted when they stopped their genocide attempt.

Two identical children in blue-and-pink sweaters remained locked in a hug as the one covered in dust cried.

**Notes for the Chapter:**

> So yeah, there will be one more chapter to wrap things up. But Frisk did it. They managed to find a pacifist solution to the situation. Granted, they also freaked out all the monsters by pulling that stunt. But there's no victory without risk. And they at least remembered some of what happened, so they knew what they were supposed to say. That doesn't mean they couldn't have been killed, though…
> 
> Anyway, I hope that you're enjoying my story. And I definitely hope that you'll like how the final chapter turns out. Thanks.


	5. Chapter 5

**Notes for the Chapter:**

> Well, this is ending up longer than expected. But I'm near the end regardless. It just takes a while to tie everything up properly. So yeah… I had to break the chapter into two chapters.
> 
> Also, it is kind of tricky writing a scene with two characters with the same name since they are the same person in different points in their life. But I think I'm managing fairly well.

" **kiddo, are ya trying to scare us to death? 'cause i really didn't need that** ," muttered Sans, sinking tiredly back into his brother's grip.

Everyone was falling into various states of surprise, shock, and relief as the entire household reacted to the scene in front of them. Sans was actually vaguely amused everyone could fit in his secret basement lab and that they all found it in the first place. It would be really distracting in different circumstances.

Sans knew he should be happy that Frisk wasn't dead. For a second, he'd been certain they were about to die. He'd known Frisk would be killed right in front of his eyes. And then just like that, the kid was out of danger and hugging the crying figure. Only Frisk could pull something off like that.

Sans should be happy, but mostly he felt overwhelmed, relieved, and worn out. In his defense, it had been a very long and stressful day with lots of shocking parts. He knew it would take time for everything to sink in. There was too much to easily handle.

"That was a close one," said Alphys. "They almost sc-scared me to death."

" **can't spell 'frisk' without 'risk'** ," Sans said quietly. " **though it would be nice if they took smaller ones occasionally. i didn't keep an eye socket on them through the entire underground just for the kid to almost kill themselves now.** "

" _Now you know how I felt watching you and your brother from the void_ ," said Gaster in an equally quiet voice, earning an interesting look from Toriel.

"So what now?" Undyne asked, drawing closer to her girlfriend. "The creepy thing around the other Frisk? That Chara person? They're gone. Frisk and… uh, Frisk… They seem to be done fighting now."

Stepping away from her ex-husband, Toriel said, "Any danger seems to have passed. We will simply have to wait for the children to finish speaking and for our Frisk to return home. And when they do," she remarked in a mildly intimidating tone, "we shall have a long discussion about how much danger they are allowed to place themselves in. Saving Sans was one thing. Allowing someone to place a knife to their throat is quite another."

Yep, the kid was definitely grounded. Frisk would be lucky if they were allowed to go anywhere other than school and home ever again. She'd lost too many children and nearly losing another was bound to scare her. But at least Frisk was alive _to_ be grounded.

* * *

"Why?" asked the dust-covered Frisk, sinking to their knees in misery. "Why did I listen? Why did I do it?"

"You were scared and angry," Frisk said, also sitting down to maintain the hug. "Chara seemed like they would keep you safe. But Chara had no Soul, only able to feel what you did to an extent. Since you were scared and angry, that's all they could feel. Fear and anger, though colder and more distant. But that also made you feel more upset and detached. Everything kept going in a loop until you started lashing out. Until you started killing. The increasing EXP and LOVE made it easier, giving you a rush and making it bother you less."

They remembered how it felt. Even fragmented from the Resets, Frisk's memories told them exactly what it was like. Chara's control took time to grow. At the beginning, those deaths were completely Frisk's doing. Even in Snowdin, where Frisk nearly stopped when faced with Papyrus, Chara could only make small decisions. Chara didn't get the ability to gain full control until their LOVE reached nineteen. Frisk knew they weren't completely in their right mind with Chara's influence, both of them corrupting and twisting each other with swirling darker emotions.

But at the end of the day, Frisk knew it was still their fault. Chara was not the one who started that nightmarish path. Chara just nearly finished it.

"They… The monsters? They really didn't want to hurt me?" whimpered the child, breaking off the embrace and wrapping their dusty arms around themselves.

Trying to be honest without scaring their past self, Frisk said, "Some would have hurt you, either by accident or because they believed they _had_ to do it so everyone could be free. But they aren't mean or evil. Most of them would rather be your friend if you tried. They aren't like the people you ran away from."

The dust-covered child sniffed sadly and rubbed their nose of their sleeve. They looked so small and young. Frisk couldn't believe there was technically only a few months difference in age between them.

"Toriel only fought you because she wanted to keep you safe. She wanted to make you change your mind and stay where she could protect you," Frisk continued, smiling briefly. "But Mom loves us more than anything and would die to protect us."

"Not _my_ mom and dad," muttered the other Frisk sadly. "They gave me up. They gave me to those people. They were supposed to come back, but they didn't. They didn't _want_ me. And… and after w-what I did here, I d-don't blame them!"

Their voice rose into a broken wail with the last few words and Frisk hugged them again. The dust-covered child sobbed quietly for a few moments more. Frisk ignored the sharp throbbing in their shoulder while calming their earlier self down. They could ignore the deep cut a little longer.

Though a piece of Monster Candy or some Nice Cream would be appreciated at the moment.

"That's why Toriel is Mom now and Asgore is my dad," Frisk said gently. "Because they love me and they'll love you too. And you didn't deserve to be given up like that. Not even now."

The other Frisk sniffed slightly, clearly feeling utterly miserable and not completely convinced. But they were listening. Frisk kept talking and hoping it would help their past self.

"Papyrus is friendly, cheerful, and good-hearted. Even if he fights you, he's the one monster who will never kill you even by accident," they described. "But not because he's weak, because he's _not_. He's just too nice and careful. He always sees the good in everyone. No matter what you do, he'll always believe in you."

The dust-covered child buried their face in Frisk's good shoulder, their sobs slowed to quiet tears. The sweater was beginning to be a real mess; tears and blood stains making it damp in places.

"Undyne is harder to get close to. She wanted to help the Underground so much, even if it meant fighting me. But she's completely loyal once she's your friend. She's brave, honorable, and tough. And she always speaks her mind and she meets every challenge head on."

Frisk smiled slightly at the thought of their friends and family. They always gave Frisk hope and would hopefully do the same for the other child.

"You never got to meet Alphys in this timeline, but she's smart, shy, and stronger than she thinks. She's really sweet and gets excited when talking about stuff she loves. She wants to help people and always tries her hardest. Even if she doubts herself, she's a great person."

The corridor was so quiet now. There was no fighting. Only Frisk's words and the other child's occasional sniffle filled the space. It seemed peaceful.

"Mettaton is bold, confident, and flashy. He loves to be the center of attention and making people smile. He never gave up on his dream to entertain the whole world and will protect that dream no matter the cost. He fought me to protect humanity so no one would start another war against them. And he really cares about his cousin."

Frisk shifted their hold on their past self a little. They winced slightly, which made the dust-covered child flinch. But at least the past Frisk seemed calmer overall.

"And Sans…" They trailed off briefly, the memory of their friend nearly dying a few minutes ago still painful for Frisk. "He's someone who has gone through a lot and deserves a happy ending. He deserves to be happy and to have a real future. He's—"

"He's your friend," interrupted the dust-covered child. "All of them are your friends. And I… I… I killed them. And I can't _fix_ it. They're gone and I can't get them back. I'm sorry."

"We _can_ fix it," Frisk assured them. "You just need to go back."

"I _can't_. If I load my Save, I'll just have to fight Sans again. And Chara might come back. Everyone will still be gone."

Frisk pulled back a little so they could look at their past self in the face. They didn't know. They honestly didn't know. Not counting their Saves, this must be their first journey through the Underground. They had never attempted a Reset before and didn't even seem to know it was possible.

"There's a way to go back to the beginning, back to when you first fell down here. Everyone will be alive again and won't really remember what happened. Of course, you won't remember most of this at first either. Just a few feelings. Those memories take time to return, even if only in pieces. But you'll have plenty of nightmares."

"I don't _want_ to remember," said the other child quietly. "I don't want nightmares. Can't I just forget forever like everyone else and pretend this never happened?"

Staring at them sternly, Frisk said, "Do you think you are above consequences?" When the dust-covered child looked away in shame, Frisk continued, "We've done a lot of terrible things. And you'll still make mistakes. And you'll die a lot to almost everyone. Except Papyrus. He'll never kill you." They shook their head briefly, not letting themselves be distracted. "Still, that much pain and misery that you caused? We can't escape consequences. You can't ignore it. If someone has to suffer for all of this, isn't it better for it to be us instead of everyone else? Living with what we've done might mean nightmares, but that's a small price to pay. We deserve worse."

Sniffling slightly, they nodded. The dust-covered child rubbed their arms slightly. They didn't look comfortable with the idea, but accepted it.

"All right." Then, looking nervous, the dust-covered Frisk asked, "If I go back to the beginning… will Chara be in my head again?"

Frisk sighed quietly and nodded. "They'll be back. But Chara is soulless and influenced by you. This time, your fear and anger twisted and corrupted them. But Chara can be shown a different purpose for their presence, a better one. Make it through the Underground without killing anyone and it'll help restore their faith in humanity and monsters alike. And they'll be able to move on."

"And how do I go back that far?" they asked.

Frisk climbed to their feet slowly. Then using their good arm, Frisk pulled their past self back upright. They gave the dust-covered child a reassuring smile.

"You know how you reached into that darkness when you load a Save? A strange void, darker than anything else and where time feels funny?" described Frisk. "You have to reach deeper, past the Save. If you reach far enough, you'll find something else. The power to Reset."

"Reset?" the child whispered thoughtfully.

Frisk nodded and said, "You'll have to wait until I leave before it'll work, but it'll take you back to the beginning. And you can do things the right way."

"But what if I do everything wrong again? If I don't remember right away, I'll just do the same things again. And I'll end up here again."

"That's why I told you about everyone. You won't remember immediately, but they'll feel familiar and you'll hesitate about hurting them again."

"How do you know?"

"Because I'm _you_ ," said Frisk. "And do you know what that means? Despite everything, it's still you."

They smiled encouragingly. The dust-covered child seemed to be taking the words to heart as Frisk continued.

"No matter what's happened, you're still you. I eventually made friends with everyone, the Barrier broke, and we live on the surface now. And that will happen for you too. You'll find your way. Trust me."

The dust-covered child gave a weak smile, appearing to be reassured a little. Both of them quietly picked up their respective weapons from the floor. The past version of Frisk grimaced briefly as they tried to wipe the blood off their blade with their sleeve and only managing to make the knife a sticky mess of blood and dust. They couldn't wipe away their sins that easily.

"It's… it's going to hurt, isn't it?"

Frisk gave them a sad smile and said, "A little. But not as much as losing to Undyne or Sans. With Chara's LOVE and EXP gone, your HP is smaller again. It'll be quick and then you can Reset."

The dust-covered child looked down at their red Soul, still floating in front of their chest and vulnerable. Both children knew the easiest way to reach the strange dark void was by dying. And even if the past version of Frisk didn't know how to use magic, there was power imbued in their weapon. It wouldn't take much to break the red object.

"Thank you for stopping Chara. And me."

" _You_ stopped Chara," said Frisk firmly. "It was your Determination that gave you back control. I just reminded you to be yourself."

"…Right. I made them stop. And I can make everything better next time," the dust-covered child said, their tone and body language growing more confident.

The idea of creating a happy ending for everyone and undoing all their mistakes… It filled the past version of Frisk with Determination.

"Don't give up, Frisk. Stay determined," they told the dust-covered child. "But that's not enough by itself. You also need to have patience, bravery, integrity, perseverance, kindness, and justice to make it through."

Frisk watched them nod and turn around, walking back across the corridor. That was their cue to leave. The child tightened their grip on their stick, spun around, and ran towards the portal. The rapid movements jostled their injured shoulder and caused a few more spikes of pain, but they didn't slow down.

They slipped through the portal just as they heard the familiar noise. Frisk tried not to flinch at the sound of a Soul shattering behind them. Then, without having to look, they felt the dark void open up behind them as the timeline ended.

" _Hit the blue button, Dr. Alphys_ ," shouted Gaster, sounding afraid of the portal now leading directly to the impossible darkeness.

"Got it."

The _whoosh_ of air signaled that the portal closed, but it didn't completely cut off the connection to the void. Frisk could still feel the darkness saturating the entire lab faintly. The void was connected to the place, just not as strongly or directly as with the portal.

Any other observations about the void and the lab were quickly shoved aside as a pair of warm and fuzzy arms wrapped around them. The white fur, the soft purple dress, and the smell of freshly-baked pies all added up to "Mom." Frisk buried themselves into the warm hug. After everything that happened, Frisk needed this. They needed their mother.

"My child, I was so worried about you," said Toriel with clearly relief.

She then pulled away a little so she could tug at their sweater, inspecting both the hole in the fabric and the deep gash in Frisk's shoulder. Judging by how her expression shifted, they suspected it looked about as bad as it felt. They didn't even bother to hide their relief as her green healing magic sank into the injury, repairing damage and soothing the pain.

"You could have been killed," she said in a far too quiet voice. Toriel stroked their hair gently, which led to Frisk leaning back against her and resuming the hug. She continued, "We shall have to have a serious conversation quite soon about all of this. It would seem there is much you have not told us."

"I know, Mom. And I'm sorry I scared everyone."

"You are also grounded for the time being for not coming straight home after retrieving him."

"Yeah, I know."

* * *

Sans watched the kid talking to their doppelganger, Frisk clearly forgetting or not caring about the rest of their audience. They didn't hold back or hesitate to say what they thought was necessary. They talked down the dust-covered child from their sobbing, they described their friends and family, and explained how to fix things. Frisk spoke gently to the other Frisk, making sure they understood the severity of their actions without destroying all hope. They explained how to Reset and reassured the dust-covered child that everything would work out eventually.

Honestly, Sans felt rather proud of the kid.

When Frisk jumped through the portal, he saw the other version move sharply. The dust-covered child's back was to them as they walked away, but he could guess what happened by the sound. Then the view of the corridor through the portal vanished, leaving them staring at something completely different.

Dark. Darker. Yet darker. Sans remembered catching a glimpse of that same darkness when the machine originally broke, when Gaster fell into the void it accessed. The timeline through the portal had ended, leaving only the void. And he couldn't tear his eyes away from the blinding darkness.

" _Hit the blue button, Dr. Alphys_ ," shouted Gaster, his tone frightened and his grip on the brothers tightening.

As if he was afraid their proximity to the void would be enough to pull him back into that darkness.

But the reptilian scientist followed orders quickly and the portal vanished with a _whoosh_. There was still something odd, a strange feeling that prickled around the edges of his mind. He just wasn't sure how to describe it. But it didn't seem dangerous and his secret lab seemed back to normal.

Well, other than not being much of a secret anymore.

Toriel reached Frisk first, wrapping them in a desperate hug that radiated maternal concern. Then she pulled back and started looking at the stab wound. Sans couldn't help cringing at what he caught a look at through the tear in the sweater. He didn't even have all the squishy stuff the kid had and he could still tell that injury looked painful. But Toriel was almost as good at healing magic as she was with fire magic and started fixing the cut without stopping the motherly affection to her child.

And unsurprisingly, she didn't have Frisk to herself for very long. Asgore, Undyne, and Alphys quickly swooped in to express their individual feelings of worry and relief. The monsters practically swarmed the child and their voices blended together in a cacophony of concern.

Sans could feel Papyrus twitch anxiously, clearly conflicted. He didn't have to look to realize that his brother was combating twin instincts. Papyrus wanted to jump to his feet and run over to welcome the child back. But he also wanted to keep holding onto Sans. And honestly, Sans didn't really want to move.

Frisk was alive and safe. Papyrus was alive and safe. Everyone he cared about was alive and safe. And he didn't seem to be in any danger at the moment either. Everything was fine for now and truthfully Sans was tired. Not the physical and almost painful exhaustion that left him on the verge of collapse, but a more general sleepiness and mental weariness. Everything was under control and it seemed like the ideal time to get some rest.

Leaning back against his brother, Sans closed his eyes. A short nap wouldn't hurt anything. He could just sleep through the current chaos and maybe avoid some of the really uncomfortable explanations for a little longer. Sans could certainly approve of that idea. Sans settled comfortably against Papyrus and let himself drift off, feeling safe and drowsy.

* * *

Gaster had long ago grown used to complete silence. While he had been scattered across time and space, aware of everything and everyone constantly in an onslaught of sights and sounds, he'd also been in the void. The void was darkness and silence. It should have been a contradiction, those opposing states. But it somehow wasn't.

This was different. While quiet, the silence wasn't complete. The machine in the corner _thummed_ softly, almost like a lullaby rather than a side effect of a tool capable of twisting the space-time continuum. Far more reassuring to him was the soft breathing, too quiet to call it snoring, of two slumbering skeletons beside him.

To be honest, Gaster wasn't surprised that Sans fell asleep. He tended to nap almost anywhere and at anytime. Furthermore, he'd certainly experienced a long and exhausting day. Even with the physical effects vanishing by returning to his proper time and timeline, the mental effects could wear on a monster. It made sense for him to drift off once the danger to him and Frisk had passed. Before Toriel completely finished checking over her injured child and healed their shoulder, Sans fell asleep on his brother's lap. And while normally a light sleeper, nothing could apparently disturb him this time. He didn't even wake up when Alphys checked him over at Gaster's insistence, making certain there were no lingering effects to his body or Soul from his near demise.

Papyrus didn't want to leave his brother alone after everything that happened, but he also didn't want to move Sans too much and risk waking him. For once, he was perfectly content to let his older brother rest undisturbed. He just wanted to hold onto Sans and pretend he hadn't nearly lost him. And if that meant both skeletons remained in the lab where Gaster could keep an eye on the pair, all the better.

Undyne brought down a couch, lifting the piece of furniture over her head to show off briefly before setting it against the wall. Papyrus settled on it comfortably while cradling his smaller brother protectively. After a little hesitation, Gaster sat down next to them. He suspected, based on her expression as everyone else shuffled out of the lab to listen to Frisk's uncomfortable explanations, Toriel knew why he wanted to stay close to them. It took a parent to recognize one.

He wasn't certain when Papyrus fell asleep, still holding his brother. Papyrus didn't sleep as often or as long as Sans generally did, the taller skeleton always filled with energy and drive. But he'd had an emotionally-trying day and deserved some rest too. So Gaster sat on the couch in his half-liquid state next to his boys and simply enjoyed having them back.

Papyrus had grown so tall since the last time Gaster truly existed in the world. He'd certainly taken after his father when it came to his height. He was amazing. Papyrus was so kind and optimistic. Papyrus was also far more aware than his brother sometimes realized. Both of them tended to hide things from the other to keep each other from worrying and to be the support their brother needed. He was a brave, loyal, and amazing skeleton. Gaster wished he shared his youngest's good heart and incorruptibility.

Even with his head tilted forward and on the verge of snoring, Gaster couldn't be prouder of Papyrus. He would have made a wonderful member of Royal Guard. And after watching his youngest child die so many times in so many timelines, it was nice to watch him in such a peaceful state.

And Sans… His eldest son forced to grow up too quickly and bearing the weight of too much crushing knowledge…

He shared his father's brilliant mind and knack for even the most complicated branches of science. He could have been an amazing scientist with countless discoveries to his name and an entire book of pun-based jokes. He had such a bright future and the drive to reach it. But when Gaster fell into the void and then that soulless husk of Asriel took control of the timeline, everything went downhill.

Over time, continued failures and the sinking realization of his helplessness eroded away at his spirit. It destroyed everything resembling optimism. His grin and jokes became a mask to hide behind as Sans succumbed to apathy and hopelessness. All of it piled on him until Sans nearly broke. Papyrus was the only thing giving him the strength to keep on living and forcing him to try. Gaster could only watch with worry from the void, afraid of what happening to his eldest son. Then Frisk took the pacifist path through the Underground, the child somehow managing to give him hope back. Sans was gradually regaining some of his old self and more of his grins were real again.

Gaster reached over and brushed his hand gently across his sleeping son's skull. He was better at maintaining a semi-solid form than before. He didn't even drip as he touched Sans, reassuring himself that his eldest son was safe.

Sans might be a smart and agile monster with rather impressive fighting strategies and attacks, but he was also fragile. Gaster remembered being terrified when the tiny skeleton was born, realizing that Sans had only a single HP and a single defense. But somehow Sans survived and grew up without suffering a fatal accident like Gaster feared. He made up for his vulnerability by learning to dodge. He never let anything hold him back. But Gaster never completely lost that fear that someday he would lose his child because of that fragility.

And it almost happened. If Frisk reacted any slower or didn't figure out how to use blue magic in time, Sans would be gone. Just when his children reached the surface and he finally had a chance to be part of their lives again, his eldest was nearly snatched away by death. He saw Sans _crumbling to dust_ …

No… He should not dwell on such dark matters. Gaster once again brushed his hand across the top of Sans' head before making a similar gesture of affection Papyrus, reaching towards his temple instead since that was as high as he could reach. Neither skeleton stirred at his touch.

His children were safe. His children were _safe_. Despite all possibilities and probabilities, both of his sons were alive and unharmed. Here and now, he had Sans and Papyrus back. That was enough for him. He'd already lost so much time he could have spent with them that he would never get back.

He'd always worked hard and for long hours as the Royal Scientist, but it only grew worse as time went on. He'd wanted to give his sons a better future, one on the surface and with an entire world of possibilities. He'd wanted to give them a future beyond the Barrier that had trapped the monsters for so long, the kind of future Sans and Papyrus deserved. And in pursuit of that goal, he missed out on so much. Sans grew up too soon caring for his brother and Gaster gradually spent less time at home with them. He'd been sure there would be plenty of time once he completed his experiments with Souls, Determination, and his time-space projects. Even when Sans, his brilliant son, followed him to the lab that awful day, Gaster still didn't give him the attention he should have. He always thought there would be time later.

And then he fell into the void and was forgotten by almost everyone. There was no time left. All he could do was watch his children from afar and regret his choices. He'd lost sight of what was most important and it was all snatched away.

But this was his second chance. Gaster would not waste this precious gift. For however long he managed to stay outside of the void, he would cherish the time he could spend with his sons. He would not take them for granted. Never again.

**Notes for the Chapter:**

> So yes, I went with the theory that Gaster is Sans and Papyrus' father. There are lots of theories about Gaster and they all have their good points, but this is the one that works best for this story. 
> 
> Plus, I was a little influenced by the web animation "Glitchtale" by Camila Cuevas on Youtube and the comic "Ask Frisk and Company" by Trash Queen, Canon Keeper and Clutter Commander on Tumblr. I highly recommend both of them. And definitely go for the season one compilation video for "Glitchtale" since it has better audio work.


	6. Chapter 6

He didn't mean to sleep as long as he did. He just intended to nap long enough to skip the reunion and awkward explanations portion of the afternoon (evening?). He fully expected someone to wake him up fairly quickly or for his nightmares to do it. But Sans could tell by the heavy feeling and slow thoughts that he'd been asleep for hours. Several hours at least. Either he was more worn out than he thought or it was a case of his laziness striking hard.

At least he didn't dream.

He didn't bother moving or opening his eyes yet. He was too comfortable for that. He wasn't in his bed, though. Sans could tell his brother still had him, cradling his brother like a little baby bones. Papyrus' grip was looser than before. It almost felt like Papyrus' arms were just resting on him limply. He still probably couldn't wiggle free though.

Someone else was stroking his head gently, reminding him of how Toriel and Asgore would run a hand through the kid's hair to comfort them. He'd done the same thing a few times. But it had been a long time since anyone did such a thing for him. A very long time. But it still felt soothing and familiar. Maybe that was part of the reason he'd slept peacefully for so long.

When Sans shifted slightly, the hand vanished from his head and the arms around him tightened just a fraction. His relaxed grin widened a little. Papyrus not only let him sleep for several hours without trying to awaken him, but he also clearly refused to let go during all that time. Honestly, he was acting like he was afraid Sans would disappear if he wasn't careful.

Like Sans almost _did_ disappear...

He couldn't prevent the shiver that shook him against his will. With all other distractions gone, the implications of the day's events were starting to sink in. He could have died. He _should_ have died.

He was hit by Chara's blade, cutting through his defense and wiping out his single HP. Sans remembered the sensation of crumbling to dust. Monsters never survived those circumstances. Once they started turning to dust, it was too late. He was _dying_. And since neither human would have been able to Save or Reset, it would have been permanent. Frisk saved him, but it was such a close call. His life nearly came to an end at the edge of Chara's knife.

His memories were a little strange too. He remembered the fight perfectly. Every moment and every emotion was vivid and intense in his mind. But everything that happened before in that timeline, all the deaths and misery, seemed... disconnected. Like he read about it happening in a book rather than experiencing it himself. Was that what it felt like for Frisk when they remembered the other timelines? He knew that Papyrus died in that timeline and that it nearly broke him when it happened, but the memory wasn't completely real. It felt like it happened to someone else. And the disconnect only made what he'd felt during the fight with Chara, all the misery, fear, and anger, feel so much stronger.

It made his near death all the more terrifying.

When another involuntary shudder took hold, the hand returned to brush the side of his head and a voice called softly, " _Sans? Are you awake? Are you all right?_ "

And that reminded him of the _other_ impossibility of the day, this one far more pleasant. Sans' eyes snapped open. He ignored the couch now in his lab and his slumbering brother. He focused on the concerned face staring down at him. Even cracked and partially melted, it was certainly him. This was real. Sans actually brought him back. It really worked.

All those years of work, all those failures, all those doubts, and the growing fear that he wasn't good enough to ever fix the machine finally paid off. Sans couldn't identify all the emotions swirling around in him, but the most prominent was joy.

" **hey there, old man** ," he said quietly, keeping his voice down to avoid disturbing Papyrus and to make it easier to keep it steady. " **haven't seen you in a while**."

" _Don't worry. I haven't been a-_ _ **void**_ _-ing you on purpose. I've missed you both far too much for that."_

Sans couldn't help it. He started chuckling. He fought to keep the noise down, but his body shook with the effort. And even as he laughed quietly, tears prickled his eyes. Gaster smiled at his own pun as nostalgia swept through the chuckling skeleton.

" _Perhaps not my best work, but at least I haven't completely lost my touch_."

" **no, that was a good one. i just didn't expect to hear a joke like that from you so soon** ," he said. Then, glancing away, he admitted, " **...** **or hear from you ever again**."

Gaster reached over and took his hand. Sans looked down at the familiar contact. The size, shape, and even the hole in the middle were all correct and exactly as he remembered. And even if there was a slight amount of give to the bones that didn't used to be there, Gaster was solid. He was real and actually there.

" **i didn't think i could fix the machine** ," Sans admitted softly, his eyes dropping briefly. " **i tried for so long until all the timeline stuff started happening and... then it didn't matter anymore. i stopped... i stopped caring about everything. i didn't try again until frisk... until they got us out. and even then... i wasn't sure i could fix it**."

" _You did not fix it_ ," said Gaster gently. " _This machine is beyond the ability for either of us to properly repair. It cannot be fixed. As I explained to your friends, you simply broke it in a particularly unique fashion. I am actually impressed. You forged a faint connection to the void, the shielding you installed to the lab keeping it contained to this room when it happened_."

" **while tossing me into a fight with a psycho** ," he muttered, not certain if he was upset that he still couldn't fix the machine or just happy it managed to drag Gaster back anyway. " **it wasn't a** _ **knife**_ **time for anyone involved.** "

The cracked and half-melted face broke into a smile at the pun. Gaster released Sans' hand so he could stroke the top of his son's head again. Honestly, this whole situation made him feel like a child again. It... was kind of nice.

" _There is still a faint connection to the void, but only within the walls of your lab. That's why I can be here now. I'm still tied to the void, Sans. As long as the half-broken machine remains operational, I can remain connected to this world_."

" **but as soon as the piece of junk stops working, you'll go back** ," Sans said, working out the rest of it. His Soul clenched tightly at the thought. " **and until then, you'll be stuck in here. you're still trapped. just trapped somewhere else. guess i didn't really do much to help ya after all.** "

" _ **Sans**_ ," said Gaster with a bit more force in his unique voice than before. " _Don't you dare think that for a moment. I missed so much of your lives already. You're grown and Papyrus is nearly grown himself. I've missed out on so much for so long. And now I have my sons back, for however long it might be. Even if I can't leave this room and whether I only have a few hours or a few years, it is worth it. I am with my children again. That is enough for me._ "

Gaster leaned forward and rested his forehead briefly against the top of Sans' head while his hand held Papyrus' arm. His expression was difficult to read as Gaster pulled away a moment later, but Sans could see that he meant every word. This was what he wanted more than anything. He wasn't disappointed in the slightest.

Sans' grin never twitched, but it felt a little more honest now. Gaster was right. This was a miracle. He and Papyrus had their father back, even if Papyrus didn't know him. His family was back to the way it was so long ago, the way he'd always wanted to go back to. For now, any other concerns could wait. This was enough.

" _Besides_ ," continued Gasater. " _I told you_ _ **this**_ _machine was beyond our ability to repair. Some parts now exist outside of time and space. We can't fix it. But there is nothing to prevent us from constructing a_ _ **new**_ _one. With proper safety precautions this time, of course. With my knowledge of the original machine's design, it should go smoother. Perhaps your friend, Dr. Alphys, could assist as well. She was helpful earlier. The three of us may be able to devise a solution. There are no guarantees, but the possibility exists_."

Sans stared silently as his words sunk in. That... might work. He couldn't really start from scratch before because he didn't have the genius mind that created it, the blueprints that were wiped from existence, nor access to the materials to construct the thing. But that was then and this was now. He didn't have to do everything alone anymore. He actually had help now. Sans chuckled quietly, feeling lighter than before.

" _ **tibia**_ **honest, that sounds good to me**."

The changes the void caused to his voice still made him seem strange compared to what he once sounded like, but his static-filled laughter brought back memories nevertheless. Gaster always laughed at his puns or smiled at Papyrus' drawings when he was small. Before his work consumed him, before the accident... This was who Gaster was. All those small details and everyday events... Sans had missed those most of all.

The click of the door opening interrupted the pair, prompting Sans to sit up as much as his brother's loose grip would allow. Quick and quiet footsteps scurried down the stairs. Sans knew those little feet quite well.

Frisk hesitated at the bottom of the stairs. Wearing their pajamas and their hair ruffled from sleep, they had a quilt wrapped around their shoulders and dragging behind them like a cape. The details that held his focus, however, were the wetness around their reddened eyes and the choking gasps shaking their small frame.

" **nightmare?** " asked Sans gently. When Frisk gave a short nod to his question, Sans gestured to them. " **come here, buddy**."

They accepted the offer instantly, running over to the couch and climbing up. Somehow managing not to dislodge anyone or wake up the sleeping skeleton, Frisk ended up on Sans' lap. And since he was still on Papyrus' lap, they ended up stacked like toy blocks. His brother could really sleep through anything when Papyrus actually bothered to sleep. Somehow the arrangement ended up relatively comfortable. The blanket unfortunately got dropped during the process, but no one seemed particularly concerned.

"I'm sorry," Frisk mumbled, wrapping their arms around him and burying their face into his shirt.

" **hey, you know the deal. no apologizing for nightmares. that goes both ways, remember?** "

Frisk didn't immediately respond. They simply fought back quiet sobs while apparently trying to burrow into his ribcage. Sans closed his eyes tiredly while running their hair between his fingers. Frisk was so mature and level-headed when dealing with everyone else's problems and facing down powerful monsters in the Underground that it was easy to forget... For all the experience they gained over the various timelines, Frisk was still just a little kid. None of this stuff should have happened to a child and sometimes it got to them.

Just like it sometimes got to him.

Both of them were quite familiar with nightmares. His had started before Frisk's arrival the Underground. The kid wasn't the first to mess with the timelines and what happened to Gaster certainly wasn't fun to watch either, so Sans had plenty of material to draw from. But it took him a little while to realize that Frisk suffered similar problems, the kid not wanting originally to worry anyone. Only when they both woke up from nightmares and tried to peek into Papyrus' room at the same time, trying to reassure themselves that he was safe, did the pair figure it out.

It became easier after that. The two of them developed a system. If one of them woke up, then they woke up the other. Sometimes that would lead to talking. Sometimes they sat in silence. Sometimes one of them would cling to the other. Other times, Sans would barely be able to look at them or Frisk would twitch at his every move. It depended on the type of nightmares, on who was dying and who was doing the killing.

Sans would see so many friends crumbling to dust. He would see Papyrus killed. He would see a child's broken body lying lifeless because of spears, because of fire, because of his own summoned bones or Gaster Blasters. Or he would see his father vanishing into an impossible darkness.

Frisk would see themselves killing friends, family, and random monsters. They would see themselves dying in a vicious cycle at the hands of those that loved them. They dreamt of a voice in their head, sometimes helpful and sometimes cruel. They would see themselves facing creatures with too much power and too many Souls that not even Sans remembered encountering. Or they would dream of things that they could never manage to explain properly, but still left them completely miserable.

But no matter what kind of awful dreams haunted their sleep, it was better when neither of them were alone afterwards. It was easier to face the nightmares together. Isolating and bottling all those feelings up never helped either of them cope.

" **want to talk about it? might make it more bear-** _ **rib**_ **-ble**."

The fact they didn't even chuckle told Sans exactly how much the nightmare affected Frisk. He leaned forward enough to rest his head on top of Frisk's. It was official. Other than Gaster's return, today hadn't been a good day for anyone.

He just waited as some of their quiet sobs began to ease. Slowly, their hug on him released and the child pulled back a little, staring at his white shirt. Then, almost timidly, Frisk traced their hand from his right shoulder diagonally toward his left side. Sans suppressed a shiver. The sensation was like the ghost of that painful and fatal cut decided to come back to haunt him. And unlike Napstablook, there was nothing nice about that ghost.

"I needed to be sure," Frisk mumbled, not meeting his eyes. "Make sure it's gone."

And that confirmed his suspicions of what exactly their nightmare entailed. He was pretty certain he would get to enjoy his own version of it in the near future. But for now, Frisk was the one having the freak out. He would have to schedule his own for another night.

Reaching for their chin, Sans forced them to look up. He gave Frisk his best comforting grin. It had to be at least mostly real or the kid would see right through it. They were far too observant to fall for fake comfort.

" **i'm fine. i'm right here and safe. no cut, no pain, and no dying. i promise. you got me back in one piece, pal**." And when Frisk rewarded him with a small and watery smile, he continued, " **and am i wrong or did you finally use blue magic? i know you've been working on that one lately.** "

" _They certainly did_ ," said Gaster before turning his gaze toward the child. " _You did very well, little one. It was very impressive._ "

"But I also hurt Sans and everyone. It wasn't all Chara."

" **i know. But it also wasn't** _ **you**_ **you. ya know? that one was all tangled up with the psycho dead kid** ," he said quietly. " **we've talked about this before. today didn't change that.** "

It was almost impossible to consider the two versions of the kid as the same person and recent events didn't change his views. This Frisk wasn't the same as the demonic thing that slaughtered the entire Underground, their eyes empty and terrifying. They weren't even the same as the broken and horrified child that this Frisk gave a pep talk to at the end. This was _their_ Frisk, the one that did everything possible to do the right thing. This was the Frisk that was nice to his brother, won Undyne's respect, boosted Alphys' confidence and self-esteem, brought Toriel back out of her isolation, and provided redemption for Asgore.

"It was still my body that did it. I almost killed you earlier. You were dying, Sans."

" **and you saved me** ," he reminded firmly. " **you kept me from being killed first by blocking chara's knife with a shield** _ **and**_ **your body. if you didn't put your shield up fast enough, you'd be the one getting sliced. then you saved me again by getting me out of there in time. face it, kid. you're great at saving people. and if you don't believe me, you've got a whole house of people who'll agree**."

As Frisk took this as a signal to return to hugging the skeleton tightly, Gaster said, " _And speaking of the others in this household, I assume your explanations went smoothly?_ "

"Mostly," mumbled Frisk. "I told them about the Saves and Resets. I told them about all the bad stuff I remember doing before I did things right. I told them about Chara. I told them a lot. But..."

" **but what, kid?** "

"I didn't tell them about Asriel. He didn't want Mom and Dad to know what happened to him, so it isn't my secret to tell. And I didn't tell them about Gaster. I thought you two should do it instead."

" **and you didn't talk about your old parents either, did you? about them getting rid of you?** "

Frisk buried their face in his shirt again. Sans felt himself tighten his grip on the child's pajamas involuntarily as he remembered what the two versions of the kids talked about. Even though he'd been distracted at the time, he'd heard enough of what the other Frisk said and what his Frisk vaguely mentioned. And he didn't like the implications.

"Mom and Dad had a lot on their mind with Chara and watching me during the fight. I don't think they noticed."

" **well, i did. So you going to tell me? 'cause it seems pretty a-** _ **parent**_ **that something happened**."

They hesitated a moment before beginning. Heavy conversations like this should probably be saved for when it wasn't the middle of the night. But most of their tough and uncomfortable discussions seemed to happen at weird hours and they were already dealing with a mountain of issues anyway. They might as well push forward.

"Humans forgot how to use magic a long time ago, but we knew that some children could almost do it. So some people collected the children who showed signs, the ones who could over time put power in objects like bandanas and ballet shoes. Or a stick. They would collect them and take them away to study. It wasn't a very nice place. They would pay parents a lot of money for those kids with potential. Like mine did," said Frisk in a dull and flat voice. "I was there a long time. And when I couldn't stay any longer, I escaped and ran away to the one place they would never go. I tried to disappear and fell into the Underground."

The grin on his face never twitched, but Sans' eyes darkened as a cold rage boiled within. He could read between the lines. How dare those people? How dare they do something like that to this child?

He pressed a hand to the back of their head, keeping Frisk's face buried in his shirt. He didn't want the kid to see and get scared. He wasn't mad at Frisk. This wasn't their fault by any stretch of the imagination.

" _What kind of cruel, heartless, and miserable creatures would do such a thing to their own child?_ " snapped Gaster, clearly struggling to keep his strange voice quiet and not awake Papyrus. " _Such people do not deserve to be parents. I would never even consider such a concept. I would not trade Sans or Papyrus for anything in the world_."

" **and that's why they're** _ **our**_ **kid now** ," Sans said quietly. " **anyone tried to take frisk anywhere and they'll be facing an army of monsters. not to mention a seriously angry tori.** "

"The place closed a month after the Barrier fell," mumbled Frisk. "I checked. Secretly."

" **good. and where do i find the humans who let you go in the first place?** "

Apparently he didn't control his voice as well as he'd hoped. Frisk pulled back to look him in the face with a concerned expression. Sans hurried to hide his cold fury with those people, brightening his eyes and forcing his grin to seem more relaxed. He could still tell that his expression was a little strained. He used to be so much better at hiding his emotions. He'd fallen out of practice since the Barrier fell. Of course, Frisk could always see right through him anyway. They could before and they could now.

"You're really mad," said Frisk uneasily. "Like back in the corridor. You're really, really mad."

" **not at you, pal. definitely not at you. this isn't because you did anything wrong. now, the heartless humans who don't deserve to be related to you... that's a different story** ," he said in a carefully controlled voice.

"Don't look for them, Sans. Don't hurt them. Just... leave them alone. I don't need them anymore," said Frisk. "I have Mom, Dad, Papyrus, Undyne, Alphys, and everyone. And you. I've got you, right?"

His anger with the unknown humans did not completely extinguish. But the way they turned the last part into a question at least shifted his thoughts to more important matters. His expression relaxed into something calmer and more genuine as Sans ruffled their hair.

" **of course ya got me, buddy** ," he said. " **that'll never change**."

Gaster chuckled gently, the strange sound filling the quiet lab. The pair glanced towards him curiously.

" _Forgive me, Sans. I was merely reminded of when you and Papyrus were small. You were always a good big brother_."

Sans didn't know how to respond to the unexpected remark, but Frisk nodded enthusiastically. The child then yawned and leaned against Sans' shirt tiredly. He honestly had no idea what time it was at the moment. There were no windows and he never got around to sticking a clock on the wall. But Sans suspected it was either really late or very early in the morning. Either way, the kid was going to a shuffling and barely-conscious mess at breakfast.

"Your dad is nice, Sans. I'm glad you got him back."

He fought back a slight chuckle. Of course Frisk figured it out. He'd only told them that he once knew Gaster before the machine broke and that he saw Gaster disappear. He told them bits and pieces, but he never fully explained. He never admitted he lost part of his family that day. But Frisk clearly made the connection anyway. The kid was always too observant and clever for their own good.

Wrapping an arm around their shoulders, he said, " **me too**."

Sans rubbed his hand briefly against their shoulder comfortingly. The kid didn't even flinch at the contact, Toriel's green healing magic ensuring the stab wound was only a memory. But the memory bothered him. He already had enough nightmares of death. He didn't want more. They could have been killed saving him. Frisk could have died permanently this time. And it would've been because of him.

" **you really risked it all to drag my sorry bones back here, didn't ya?** " he said quietly. " **not sure i'm worth it.** "

Any signs of sleepiness vanished as Frisk pulled back and directed a rather stern look at him. The expression lost a little of its effectiveness due to their age, their pajamas, and their bed-head, but it still got their point across. Frisk apparently thought he was an idiot.

"Of _course_ you're worth it. You're my friend."

" **kid, you could have died**."

"I've died a lot already. I've died a lot in that corridor specifically," said Frisk far too casually. "That doesn't change anything. You're my friend. And if it meant saving you, getting killed again would be worth it."

" **but you couldn't _reset_** ," Sans said with a bit more force than he meant to use. " **it wouldn't be like all those fights in the past. you said you couldn't reset. you would be gone, frisk**."

"It didn't matter that I couldn't Save or Reset there."

" **it would have if you died. you-** "

"It wouldn't matter," interrupted Frisk, "because I wouldn't have tried loading a Save or a Reset anyway."

That stopped Sans cold. He stared at the child on his lap and tried to decide if he heard them correctly.

"... **what?** "

"I promised, remember? I promised you no more Resets. I meant it. No matter what happens to me, I won't do it."

Two opposing and powerful emotions hit him hard. Sans felt horrified and guilty to realize the kid really would let themselves die rather than break that promise. Frisk made that promise a while ago, but he'd always had his doubts. Hope was scary. Allowing himself to believe them completely would be too hard. This time, he could see their honesty and Determination. The child would rather be killed permanently than force him and the others back into that endless cycle of repeating timelines.

The other emotion the realization caused was relief. And his relief over truly escaping the Resets forever made the guilt worse.

" **frisk, i honestly don't know what any of us did to deserve a great kid like you** ," he said finally. " **thanks for saving me, by the way. i don't know if i said it earlier, but thank you**."

"YEAH," shouted Papyrus, making everyone jump in surprise. While they struggled to recover from the unexpected noise, he engulfed Sans and Frisk in an impromptu group hug. "THANK YOU SO MUCH FOR SAVING MY BROTHER. I'M SO HAPPY THAT EVERYONE IS SAFE AND UNHARMED."

" **uh... hey, bro? how long have you been awake and listening?** "

Narrowing his eyes at his older sibling, Papyrus said, "LONG ENOUGH, BROTHER. LONG ENOUGH. AND I HAVE ONE IMPORTANT QUESTION."

He turned his head sharply and pointed towards the partially-melted monster beside him. Gaster jerked back slightly in surprise while the skeleton's eyes practically popped out.

"I HAVE A DAD?"

* * *

Toriel should have been more upset to find her child's bed empty that morning. Not only was Frisk grounded until further notice, but she didn't have much sleep the night before. Everything she'd seen and learned yesterday was too much. She was having trouble handling it all. Discovering her child missing should have been the final straw.

But she found herself not overly concerned. She already had her suspicions of where to look.

Far quieter than her ex-husband would have managed, Toriel slipped out of the house, walked around the building, and opened the concealed door to the formerly-secret basement lab. She would certainly have to commend Sans on the construction of the extra room at a later date. She then quietly crept down the stairs.

The scene she found brought a smile to her face.

Frisk was curled up on Sans' lap and sleeping quietly. They had practically latched onto, their arms encircling the skeleton while their hands vanished under his coat. Sans returned the favor by hugging the child close like an oversized stuffed toy. He slept with his head nestled on top of Frisk's hair.

Furthermore, Sans rested on Papyrus' lap. His longer arms wrapped around the smaller skeleton and human child quite comfortably. There was no danger of anyone slipping off and falling off the couch. And Papyrus seemed to be leaning against the new monster, Gaster. Even though he might be half-melted and strange, Gaster at least appeared to be sleeping lightly and solid enough to lean back against the snoozing skeleton.

Toriel had a few theories about the newcomer, but for now all that mattered was that he helped complete the rather adorable image before her. She was honestly tempted to sneak back up to the rest of the house and locate a camera.

Instead, she reached down and picked off the quilt from where it had fallen. Then Toriel carefully draped it across the four sleeping figures. There was no reason why they should not be allowed to sleep a little longer.


End file.
